• 한국산업융합학회 논문집
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• 제22권4호
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• pp.447-457
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• 2019

The intelligent sensory system is required to ensure the accurate welding performance. This paper describes the development of an intelligent vision sensor for the robotic laser welding. The sensor system includes a PC based vision camera and a stripe-type laser diode. A set of robust image processing algorithms are implemented. The laser-stripe sensor can measure the profile of the welding object and obtain the seam line. Moreover, the working distance of the sensor can be changed and other configuration is adjusted accordingly. The robot, the seam tracking system, and CW Nd:YAG laser are used for the laser welding robot system. The simple and efficient control scheme of the whole system is also presented. The profile measurement and the seam tracking experiments were carried out to validate the operation of the system.

• International Journal of Korean Welding Society
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• 제2권1호
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• pp.45-51
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• 2002

In the multi-pass welding of pressure vessels or ships, the mechanical touch sensor system is generally used together with a manipulator to measure the gap and depth of the narrow gap to perform seam tracking. Unfortunately, such mechanical touch sensors may commit measuring errors caused by the deterioration of the measuring device. An automation system of narrow gap multi-pass welding using a laser vision system which can track the seam line of narrow gap and which can control welding power has been developed. The joint profile of the narrow gap, with 250mm depth and 28mm width, can be captured by laser vision camera. The image is then processed for defining tracking positions of the torch during welding. Then, the real-time correction of lateral and vertical position of the torch can be done by the laser vision system. The adaptive control of welding conditions like welding currents and welding speeds, can also be performed by the laser vision system, which cannot be done by conventional mechanical touch systems. The developed automation system will be adopted to reduce the idle time of welders, which happens frequently in conventional long welding processes, and to improve the reliability of the weld quality as well.

• 한국의류산업학회지
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• 제4권2호
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• pp.137-144
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• 2002

This study was to provide the fundamental data for a scientific and rational clothing construction by investigating the variation of the upper body surface with the use of the method of Surgical tape. The subject were 3 middle elementary schoolboys classified standard somatotype, and arm-movements were consisted of 6 types. The statistical analyses used in this study were mean, standard deviation and the ANOVA and LSD procedure. Shoulder point was moved to be the inside or upside and the shape of the armhole-line was differently changed as the arm-movement become larger. By moving to upside of the anterior armpit point, posterior armpit point and armpit point, the increase of the side seam length and the ascent of the line of width between armpits were distinct. And by arm-movements, in the items of horizontal, front neck base girth, back upper bust girth, back bust girth and back waist girth were increased and the other standard lines were apt to be decreased. In the items of vertical, all standard lines of front side and side seam length showed increased, back waist length and back length showed decreased. The variation of armhole was indefinite. In the rate of the variation, the shoulder length showed the maximum rate of contraction by 41.3%, decreasing 3.7 cm in $180^{\circ}$ degrees, and the side seam length showed the maximum rate of expansion by 60.6%, increasing 8.97 cm in the same degrees.

• 대한공간정보학회지
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• 제12권2호
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• pp.61-66
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• 2004

최근 위성 탑재 센서의 종류와 영상의 공간해상도가 다양해지고 서로 다른 시기에 관측 수집된 영상자료를 모자이크하여 지형공간정보체계(GIS)와 같은 응용분야에서의 활용에 대한 필요성이 점차 커지고 있다. 영상 모자이크에는 영상정합, 분광정보 조정과 같은 다양한 기법들이 필요하다. 웨이블렛 변환 기반 영상정합 기법을 적용하여 영상 모자이크의 자동화에 대해 연구하고자 하였다. 본 논문에서는 폴리곤 클리핑 기법을 적용하여 두 영상에서 중복 영역을 추출하고자 중복영역에 대하여 형상 기반 정합과 영역 기반 정합을 동시에 적용하는 웨이블렛 변환 기법을 이용함으로써 자동으로 접합점을 추출하였다. 또한 영상 모자이크를 수행함에 있어서 두 영상의 분광 정보를 조정하기 위한 방사 보정기법은 히스토그램 정합 기법을 적용하여 연구 분석하였다. 본 연구에서 적용한 폴리곤 클리핑 기법 결과로 중복영역과 모자이킹 영역을 자동을 추출할 수 있었다. 그리고 다해상도 웨이블렛 분석 기법을 이용하여 특징점에 대해 영상정합을 수행하고 이를 이용하여 모자이킹 접합선을 추출한 결과 접합부분에서 불연속 부분 없이 모자이킹 영상을 생성할 수 있었다.

• 한국의류학회지
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• 제20권6호
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• pp.1107-1115
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• 1996

An investigation made of the easing contraction ratio according to sewing condition (seam line; wp, wf, 45$^{\circ}$ bias, stitch density; 13 stitch/cm (0.8 mm), 9 stitch/cm (1.1 mm), 6.5 stitch/ cm (1.5 mm), 5 stitch/cm (2 mm), 4 stitch/cm (2.5 mm), thread; sp 60$^{\circ}$s/2, sp 60$^{\circ}$s/3, st 60$^{\circ}$s/3, st 50$^{\circ}$s/3)) by lockstitch industrial sewing machine with shirring foot. The correlations of the easing and sewing conditions were by SPSS PC), and visual test was done by enlarged photo. The results obstained were as follows:. 1. The easing contraction ratio is increased in proportion to the low of stitch density. 2. The easing contraction ratio of wp, 45$^{\circ}$ bias is correlated with stitch density, and that of wf be with stitch density, elongation & weight. 3. The easing contraction ratio of 13 stitch/cm (0.8 mm), 9 stitch/cm (1.1 mm), 6.5 stitch/ cm (1.5 mm), 5 stitch/cm (2.0 mm) is correlated with flexible rigidity, and that of 4 stitch/ cm (2.5 mm) be with flexible rigidity and crease-resistance. 4. As a results of SPSS PC+ statistics, the easing contraction ratio is statistically correlated to the seam line, stitch density, upper thread tension, and fabric characteristics. 5. As a results of visual test by the enlarged photo, the limit of stitch density for easing contraction was 5 stitch/cm (2.0 mm).

• 한국레이저가공학회지
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• 제12권3호
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• pp.14-17
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• 2009

The laser welding was performed for the flange joint of two overlapped coaxial circular pipes which serve as the inlet and connector pipes of STS 316L. The laser welding test finally resulted in a good penetration depth of 1.8 to 2.0 mm. On the way to get the good welding quality, two important parameters were found to be optimized. One is the focal positioning which is the offset of the laser beam focus to the exact welding seam line, which is more critical in the inner flange laser welding. When the beam spot size was deviated more than $200\;{\mu}m$ from the seam line, welding of two pipes is failed. The other is a gap size since a certain amount of gap is inevitable due to fabrication tolerance, or artificial allowances for smooth insertion of a pipe. However, it is required to restrict the gap allowance within 0.2mm to avoid undesirable undercut on a welding bead.

• 대한공간정보학회지
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• 제17권3호
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• pp.33-40
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• 2009

본 연구에서는 모자이크 영상에 대하여 정량적인 품질평가지수에 대한 적용 가능성을 제시하였다. 우선, 영상 품질평가를 위해 접합영상의 접합선을 이용한 연속성 평가와 색상을 이용한 유사성(similarity) 및 대비(contrast)를 이용하여 품질평가지수를 산정하였다. 선정된 품질평가 항목을 기반으로 최종적인 품질평가지수를 산정하여 실험자에 의한 주관적 평가와의 비교, 검증을 수행하였다. 그 결과 정량적 품질평가지수가 주관적 평가지수와 유사한 결과를 나타냄으로써 제시한 영상 품질평가지수를 이용하여 제작된 모자이크 영상에 대한 정량적이고 객관적인 모자이크 영상의 품질평가가 가능하다는 것을 보여주었다.

• 방송공학회논문지
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• 제24권6호
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• pp.992-1001
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• 2019

다수의 카메라를 이용하여 취득된 영상을 정합 하여 하나의 넓은 시야각을 가지는 영상을 합성하는 기술이 많은 영역에서 사용되고 있다. 영상의 정합 영역 내에 이동 객체가 등장한 경우 객체의 왜곡 없이 영상을 정합 하기 위하여 움직임 정보를 이용하는 시접선 추정 방법을 제안한다. 기존 시접선 추정 기반 기술들은 영상 외곽선 정보와 시차 등을 이용하여 에너지 함수를 형성하고 시접선을 추정하는 방법을 사용하여 왔으나, 본 논문에서는 프레임 별 외곽선 정보를 이용하여 움직임 정보를 계산하고, 이를 에너지 함수에 반영하여 영상 정합 시 이동 객체의 왜곡을 방지하는 시접선 추정 기술을 제안한다. 또한, 정합 영상의 왜곡 정도를 정량화 할 수 있는 지표를 제안하여 기존 기술과 제안된 방법의 성능 차이를 검증한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.56.3-56
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• 2002

For the weld quality improvement and the convenient operation of machines, laser vision system can be used to track weld seams on pressure vessels. There are many bad conditions to the weld grooves such as cutting error, gap variation of weld joint, and offset error of center line caused by misalignment. We developed a laser vision seam tracking system which consists of a laser vision sensor, a two axis positioning mechanism and a user interface program running on the Windows system. It was found that our system worked well for U, V and X shaped grooves. We used an industrial PC as the system controller to secure immunity to electrical noise and dust. We introduce here a simple and...

• International Journal of Precision Engineering and Manufacturing
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• 제4권6호
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• pp.20-28
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• 2003

This paper presents development of a high speed rotating arc sensor system using a microprocessor based controller with tracking function for a complicate curved fillet welding line, The welding tip connected to the torch body is eccentrically positioned from the centerline of the torch, The area during one rotating cycle is divided into 4 regions of front, rear, right and left in welding direction of the torch tip to determine the horizontal deviation between the welding seam and the torch position. The average value at each region is calculated using the regional current values and a low pass filter incorporated with the moving average method is implemented. The effectiveness of the developed system is proven through the experimental results for several kinds of complicate curved fillet welding lines.