• 한국광학회지
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• 제27권5호
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• pp.165-173
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• 2016

본 연구는 2개의 라인 레이저를 이용하여 3차원 형상을 획득하는 방법에 대해 제안한다. 제안하는 방법은 532 nm와 630 nm 파장의 레이저를 이용하여 2-라인 레이저를 생성하고 이를 대상객체에 조사하여 반사되는 빛을 영상센서로 획득하는 것을 통해 3차원 점 데이터를 연산한다. 이를 위해 레이저와 카메라 간의 위치를 결정하고 각 레이저의 평면 방정식 계수를 추정하며 삼각법을 통해 이미지 공간의 라인을 3차원 공간의 점으로 변환한다. 제안하는 시스템은 2개의 라인 레이저와 데이터 정합을 위한 스태핑 모터 제어부와 영상을 획득하고 레이저의 라인을 추출하는 영상처리부, 그리고 추출된 라인으로부터 3차원 점 데이터를 처리하고 3D 모델을 생성하는 3D 모델링부로 나뉜다. 제안하는 방법은 기존 단일 레이저 스캐닝 방식과 비교하여 가려짐으로 인해 발생하는 데이터 소실문제를 해결할 수 있다.

• 전기화학회지
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• 제9권2호
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• pp.84-88
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• 2006

본 연구에서는 주사탐침현미경을 이용한 Si 표면의 국부 산화피막 형성에 있어서, 탐침이 움직이면서 생기는 $SiO_2$의 일차원적인 선의 높이가 탐침 전위, deflection setpoint, 탐침 속도에 의해 어떻게 영향을 받는지 고찰해 보았다. -3 V 보다 작은 탐침 전위에서는 국부 산화피막 형성이 관찰되지 않았으며 -3 V 보다 큰 탐침 전위에서는, 탐침 속도가 $1{\mu}m/s$일 때, 1 V씩 증가함에 따라 0.47nm의 비율로 선의 높이가 높아졌다. Deflection setpoint는 탐침이 가하는 기계적인 힘의 표지가 되는데, $12\sim18nN$ 정도의 힘이 가해지지 않으면 국부 산화피막 형성이 관찰되지 않았다. 그 이상의 힘이 가해져야 국부 산화피막 형성이 관찰되는데 이때 선의 높이는 기계적인 힘과 무관하였다. 탐침 속도가 빨라짐에 따라 선의 높이는 낮아졌으나, 탐침 전위가 -5V인 경우, 0.7nm 이하로 낮아지지는 않았다.

• 대한임베디드공학회논문지
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• 제12권1호
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• pp.43-62
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• 2017

Mobile pulse scanning Light Detection And Ranging (LIDAR) are essential components of intelligent vehicles capable of autonomous travel. Obstacle detection functions of autonomous vehicles require very low failure rates. With the increasing number of autonomous vehicles equipped with scanning LIDARs to detect and avoid obstacles and navigate safely through the environment, the probability of mutual interference becomes an important issue. The reception of foreign laser pulses can lead to problems such as ghost targets or a reduced signal-to-noise ratio. This paper will show the probability that any two scanning LIDARs will interfere mutually by considering spatial and temporal overlaps. We have conducted four experiments to investigate the occurrence of the mutual interference between scanning LIDARs. These four experimental results introduced the effects of mutual interference and indicated that the interference has spatial and temporal locality. It is hard to ignore consecutive mutual interference on the same line or the same angle because it is possible the real object not noise or error. It may make serious faults because the obstacle detection functions of autonomous vehicle rely on heavily the scanning LIDAR.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.884-886
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• 2012

일반적으로 사용하고 있는 X-선 검색장치는 대상물의 단면 정보만을 제공하고 있기에 검색 대상체를 식별에 어려움이 있어 이에 대한 개선이 요구되어 왔다. 스테레오 X-ray 시스템은 기존의 검색장치에 라인센서를 추가하여 검색 대상체에 대한 추가적인 정보를 제공함으로써 검색 효율을 높이도록 고안되었다. 본 논문에서는 선행 연구를 통해 개발된 스테레오 X-선 검색장치의 검색 속도를 향상시키기 위하여 정밀제어를 위한 제어부를 설계하고 이를 통해 이동체와 검색기의 스캔 속도를 동기화 하고 대상체의 검색 속도를 개선하였다. 본 연구의 결과는 대형 화물 스캔 장치 및 고속화물 스캔 장치 개발을 위해 활용될 수 있다.

• 비파괴검사학회지
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• 제27권3호
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• pp.246-254
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• 2007

The scanning laser source (SLS) technique is a promising new laser ultrasonic tool for the detection of small surface-breaking defects. The SLS approach is based on monitoring the changes in laser-generated ultrasound as a laser source is scanned over a defect. Changes in amplitude and frequency content are observed for ultrasound generated by the laser over uniform and defective areas. The SLS technique uses a point or a short line-focused high-power laser beam which is swept across the test specimen surface and passes over surface-breaking or subsurface flaws. The ultrasonic signal that arrives at the Rayleigh wave speed is monitored as the SLS is scanned. It is found that the amplitude and frequency of the measured ultrasonic signal have specific variations when the laser source approaches, passes over and moves behind the defect. In this paper, the setup for SLS experiments with full B-scan capability is described and SLS signatures from small surface-breaking and subsurface flaws are discussed using a point or short line focused laser source.

• 제어로봇시스템학회논문지
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• 제17권11호
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• pp.1159-1167
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• 2011

A novel 3D tube scanning technique is proposed. The proposed tube scanning technique is developed for a special tube inspection module which consists of four line-lasers and one camera. Using the scanning module, we can reconstruct the 360 degree shapes of the inner surfaces of a cylindrical tube. From an image frame captured by the camera, we reconstruct a partial tube model based on four laser triangulations. Then by aligning such partial models with respect to a reference tube axis, a complete 3D shape of the tube is reconstructed. The tube axis in each reconstructed frame is aligned with a 3D Euclidean transformation to the reference axis. Several experiments show that the proposed method can align multiple tube axes very accurately and reconstruct 3D shapes of a tube with very low shape distortion.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.202-205
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• 2002

This paper describes the spot scanning with $^{11}$ C beams for the Heavy Ion Medical Accelerator in Chiba (HIMAC). The concave-shaped irradiation field was optimized and the dose distribution was measured by 128-ch ionization chamber. Because of the wide momentum spread inherent in $^{11}$ C beams, the dispersion caused from the beam line and the scanning magnets should be taken into account to calculate the dose distribution of $^{11}$ C beams and their irradiated field. The reconstructed dose distribution is in good agreement with the experimental results.

• Progress in Superconductivity
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• 제13권3호
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• pp.169-177
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• 2012

Distribution of the local properties in GdBCO and YBCO coated conductors was investigated using Low-temperature Scanning Laser and Hall Probe Microscopy (LTSLHPM). We prepared GdBCO and YBCO coated conductors to study the spatial distribution of the current density in a single bridge. Inhomogeneity of the ${T_c}^{max}$ in the bridge was analyzed from experimental results of Scanning Laser Microscopy (SLM) near the superconducting transition. The local transport and screening current in the bridge were also investigated using Scanning Hall Probe Microscopy (SHPM). A series of line scans of SLM of the GdBCO and YBCO sample showed that lines with more inhomogeneous distributions of ${\delta}V$ had more inhomogeneous distributions of ${T_c}^{max}$. The defect of the superconducting layer of the GdBCO sample caused by damage to the substrate affected the current flow. And we could analyze the redistribution of the current density using SLM and SHPM.

• 한국기계가공학회지
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• 제8권2호
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• pp.25-31
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• 2009

The image processing methods are widely used in many industrial fields to detect defections in inspection devices. In this study an image processing method was conducted for the detection of abnormal pixels in a OLED(Organic Light Emitting Diode) type panel which is used for small size displays. The display quality of an OLED device is dependent on the pixel formation quality. So, among the so many pixels, to find out the faulty pixels is very important task in manufacturing processing or inspection division. We used a line scanning type BW(Black & White) camera which has very high resolution characteristics to acquire an image of display pixel patterns. And the various faulty cases in pixel abnormal patterns are considered to detect abnormal pixels. From the results of the research, the normal BW pixel image could be restored to its original color pixel.

• 한국정밀공학회지
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• 제15권12호
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• pp.97-105
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• 1998

The fiber oriented condition inside fiber reinforced composite material is a basic factor of mechanical properties of composite materials. It is very important to meausure the fiber orientation angle for the determination of molding conditions, mechanical characteristics, and the design of composite materials. In the work, the fiber orientation distribution of simulation figure plotted by PC is measured using image processing in order to examine the accuracy of intersection counting method. The fiber orientation function measured by intersection counting method using image processing is compared with the calculated fiber orientation function. The results show that the measured value of fiber orientation function using intersection counting method is lower than the calculated value, because the number of intersection between the scanning line and the fiber with smaller fiber aspect ratio is counted less than with larger fiber aspect ratio.