• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.517-518
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• 2007

A method to recognize unpaved road region using a 3D depth measurement system is proposed for mobile robots. For autonomous maneuvering of mobile robots, recognition of obstacles or recognition of road region is the essential task. In this paper, the 3D depth measurement system which is composed of a rotating mirror, a line laser and mono-camera is employed to detect depth, where the laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The obtained depth information is converted into an image. Such depth images of the road region represent even and plane while that of off-road region is irregular or textured. Therefore, the problem falls into a texture identification problem. Road region is detected employing a simple spatial differentiation technique to detect the plain textured area. Identification results of the diverse situation of Nonlinear trail are included in this paper.

• The Journal of the Acoustical Society of Korea
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• 제14권2E호
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• pp.73-86
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• 1995

전향 초음파 영상 캐서터의 트랜스듀스 (FLUIC) 부분은 진동자인 원형 전기음향 소자와 원뿔꼴 반사체인 음향 반사체로 구성된다. 소형의 전기음향 소자는 캐서터의 회전자 축 측면에 탑재된다. 전향 초음파 영상 캐서터의 특징은 기존의 IVUS 트랜스듀서가 제공할 수 없는 캐서터 전단에서 혈관의 단층 2-D 영상과 종래의 측면 영상을 동시에 제공하는 것이다. FLUIC의 트랜스듀서에 사용된 음향 반사체를 설계하기 위해 근사화된 레이 추적 기법을 이용하였다. 음향 반사체로부터 2차 외절 특성을 예측하기 위해 회절전달함수방식에[1] 의한 1차 음원으로 부터의 장 예측모델을 확장하여 일반화 하였다. 확장된 모델은 단순한 평판 반사체에 적용하여 시뮬레이션과 실험에 의해 검증되었으며 FLUIC의 잘 특성을 해석하는데 사용되었다.

• 한국광학회지
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• 제28권5호
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• pp.213-220
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• 2017

3D 프린터와 반도체 레이저를 사용하여 정렬하기 쉽고 저렴한 교육용 마흐젠더 간섭계를 제작하는 방법을 제안하였다. 간섭계는 $165mm{\times}120mm{\times}57mm$ 크기의 몸체, 거울 마운트, 레이저 홀더, 광분할기 등으로 구성된다. 레이저 경로는 고무 밴드, 작은 금속 막대 및 나사로 구성된 4개의 거울 마운트로 조정하였다. 간섭무늬는 최종 단계에서 렌즈에 의해 확대되었다. 슬라이드 글라스의 굴절률은 간섭계 팔 중 하나에 삽입된 슬라이드 글라스가 회전하는 동안 이동하는 간섭무늬의 수를 계수함으로써 측정되었다. 굴절률을 구하는 식을 광경로차와 회전 각도의 함수로 찾았으며, 간섭계 실험에서 유리의 굴절률을 계산하는데 사용하였다. 간섭계의 한 팔에서 유리를 회전시키면 교실에서 움직이는 간섭무늬를 관찰하기 위해 고가이지만 사용되었던 정밀 스테이지가 필요 없게 된다. 따라서 이 논문에서 제안 된 3차원 프린터로 제작한 마흐젠더 간섭계는 경제성과 성능 때문에 교육에 매우 유용할 것으로 기대된다. 학생들이 3차원 프린터로 제작한 간섭계를 사용하여 유리의 굴절률과 빛의 파장을 측정하는 등의 정성적 및 정량적 연구를 수행 할 수 있을 것이다.

• International Journal of Control, Automation, and Systems
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• 제3권1호
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• pp.130-136
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• 2005

A new optical digitizing system for determining the position of a cursor in three dimensions(3D) and an experimental device for its measurement are presented. A semi-passive system using light intensity modulation, a technology that is well known in radar ranging, is employed in order to overcome precision limitations imposed by background light. This system consists of a charge-coupled device camera placed before a rotating mirror and a light-emitting diode whose intensity is modulated. Using a Fresnel pattern for light modulation, it is verified that a substantial improvement of the signal to noise ratio is realized for the background noise and that a resolution of less than a single pixel can be achieved. This opens the doorway to the realization of high precision 3D digitized measurement. We further propose that a 3D position measurement with a monocular optical system can be realized by a numerical experiment if a linear-period modulated waveform is adopted as the light-modulating one.

• 전자공학회논문지B
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• 제31B권1호
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• pp.49-56
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• 1994

This paper describes the design principles and methods of electronic processor for thermal imager with the SPRITE detector, operating in the 8-12 micron band. The thermal imager consists of a optical scanner containing the detector and an electrical signal processor. The optical scanner utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using 5 elements of the detector. And the electronic processor has pre-processing of 5 chnanel's thermal signal from the detector, and performs digital scan conversion to reform the parallel data stream into serial analog data compatible with conventional RS-170 video. Through the designed electronic processor, we have acquired a satisfactory thermal image. And the MRTD (Minimum Resolvable Temperature Difference) is 0.5$^{\circ}$K at 7.5 cycles/mm.

• 한국분무공학회지
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• 제4권1호
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• pp.13-18
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• 1999

It has been known that spray characteristics have an important effect on the mixture formation and directly influence the engine performances and the emissions. Up to now, the measurement of droplet size is well developed such as PDPA and PMAS though the behavior of small droplets during secondary atomization is not clear. Particle image velocimetry(PIV), a planar measuring technique, is a very efficient tool for studying complicated behavior and a fast and reliable method to track numerous droplets during injection. In this study, two-color scanning PIV is designed to obtain quasi-instantaneous two dimensional velocity data by using he-ion laser, rotating mirror and beam splitter. This PIV method which has high temporal and spatial resolution provides the information about the small complex droplet behavior.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1250-1254
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• 1992

This paper describes the designed and fabricated thermal imaging system with the SPRITE(Signal PRocessing in The Element) detector, operating in the 3-12 micron band. This system consists of an afocal telescope, a scan unit containing the SPRITE detector, an electronic processor unit and a cooler. The optical scan system utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using five elements of the detector. And the electronic processor unit performs digital scan conversion to reform the parallel data stream into serial analog data compatable with conventional RS-170 video. The scan field of view is 40 ${\times}$ 26.7 and the MRTD(Minium Resolvable Temperature Difference) is 0.6 K at 7.5 cycles/mm. The acquired thermal image indicates that this system has a satisfactory performance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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• pp.5-5
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• 2010

The depth of the object pointed by the laser beam is computed depending on the pixel position on the CCD There involved several number of internal and external parameters such as inter-pixel distance, focal length, position and orientation of the system components in the depth measurement error. In this paper, it is shown through the error sensitivity analysis of the parameters that the most important parameters in the sense of error sources are the angle of the laser beam and the inter pixel distance. Also, the calibration technique to minimize their effect for the depth computation is proposed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.759-762
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• 2002

Automobile aeroacoustics Is a developing area of technology where experimental and theoretical tools are being continuously refined to understand, analyze and modify the noise-generating mechanisms in the vehicle flow. Main sources of ground vehicle exterior noise are the tires (tire/road interaction) and the unsteady flow field around the vehicle. In this study, the sound source localization of a rolling tire was applied to the measurement of radiated sound by using an acoustic mirror system. A possible flow pattern that develops is suggested based on detailed wind tunnel investigations with a rotating wheel in contact with a moving belt.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.273-276
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• 1997

Seeing is an intelligent act. Retina is the most important part among the components of eye which is comprised of iris, pupil, lens, optic disk, and so forth. Because retina acts like a photo receiver to detect light from every object, if damaged, animals have a severe problem to live along with themselves and sometimes they lose their sight. In the ophthalmology, doctors use special instrument to see exact retina image of object and operate the surgery by rotating focus control knob. In this study, a basic test is done to achieve the auto focus control instrument. Specially made sledge and attenuator are installed on the optic bed to change the distance and laser power between the first reflective mirror and the second one. Control panel which is compiled by Visual C t t to control stepping motors ,laser power and photodiode are implemented with ADA-board.