• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.91-97
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• 2000

In this paper, the illuminator is designed to recognize the shape and the existence of holes of radiation fin in the point that the light reflection characteristics are different according to the roughness of the material. The threshold value, the positions of holes and the black pixel nembers in the positon are obtained under the illuminator, in accordance with the reference image, by applying binary conversion and hole segmentation algorithm, as they are suggested in this paper, The existence and shape of hole are recognized by calculating the distance and feature value in the test image, which is obtained from the parameters of reference image. It is programmed to apply to GUI(Graphic User the Interface) in windows. More than 98% of recognition rate is shown, as it is applied to three different sizes of the radiation fin.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.5
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• pp.469-475
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• 2010

This paper presents a method of classifying discolored defects of metal pads using geometric texture for AFVI (Automated Final Vision Inspection) systems. In PCB manufacturing process, the metal pads on PCB can be oxidized and discolored partly due to various environmental factors. Nowadays the discolored defects are manually detected and rejected from the process. This paper proposes an efficient geometric texture feature, SUTF (Symmetry and Uniformity Texture Feature) based on the symmetric and uniform textural characteristics of the surface of circular metal pads for automating AFVI systems. In practical experiments with real samples acquired from a production line, 30 discolored images and 1232 roughness images are tested. The experimental results demonstrate that the proposed method using SUTFs provides better performance compared to Gabor feature with 0% FNR (False Negative Rate) and 1.46% FPR (False Positive Rate). The performance of the proposed method shows its applicability in the real manufacturing systems.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.361-362
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• 2007

We propose a contrast-controlled feature detection approach for steel radiograph image. X-ray images are low contrast, dark and high noise image. So, It is not simple to detect defects directly in automated radiography inspection system. Contrast enhancement, histogram equalization and median filter are the most frequently used techniques to enhance the X-ray images. In this paper, the adaptive control method based on contrast limited histogram equalization is compared with several histogram techniques. Through comparative analysis, CLAHE(contrast controlled adaptive histogram equalization) can enhance detection of defects better.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.229-240
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• 1998

In these days, we are facing the needs of the times that the product have to be converted from quantity to quality. Most companys now pay more attention to maximize efficiency of facilities with introducing high priced equipments, those equipments are too automated and electronic that partial failure or short time stop leads to the stop of producing process in the whole factory. Consequently, effective maintenance management of production equipment becomes a only solution against problems. This thesis develops a preventive maintenance software that grasp a failure sign through daily inspection with management item, Machine-Capability index and estimate a trend, determine the time of preventive maintenance. The software is useful to the plant operator in analyzing information easily and controlling preventive maintenance operations efficiently.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.340-342
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• 2006

기존의 PCB 자동시각검사 시스템은 창조 비교 방법을 위한 참조 영상(골든 영상) 획득에 많은 어려움을 겪고 있다. 이러한 문제를 해결하기 위하여 본 연구에서는 PCB 제작에 사용되는 CAD 파일을 이용하여 참조 영상을 생성함으로써 학습을 좀 더 쉽고 간??하게 할 수 있는 시스템을 구현하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.859-861
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• 2005

레이저 프린터의 드럼 자동시각 검사 시스템은 사람의 육안 검사를 자동화함으로써 정확하고 신속한 제품 검사가 가능하도록 한다. 또한 검사 결과를 데이터베이스화함으로써 지속적인 불량 발생 요인을 찾아 조치할 수 있어 불량률 감소와 제품 신뢰도 향상을 도모할 수 있다. 본 연구에서는 레이저 프린터 드럼의 표면에 발생하는 결항을 자동으로 검사하는 시각 검사 시스템을 구현하였고 이를 적용하여 신속하고 정확한 검사가 가능함을 보였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.862-864
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• 2005

자동차 전자 부품 중 하나인 정션박스의 자동 시각 검사 시스템은 사랑의 육안 검사를 자동화함으로써, 정확하고 빠른 검사가 가능하다. 또한 검사 결과를 데이터베이스화하여 지속적인 불량 발생요인을 분석할 수 있기 때문에 불량률을 감소시켜 제품 신뢰도를 향상시킬 수 인다. 본 연구에서는 정션박스에 삽입된 퓨즈와 릴레이의 유무 및 오결합을 자동으로 검사하는 자동 시각 검사 시스템을 구현하였고 이를 적용한 결과 신속하고 정확한 검사가 가능함을 보였다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.424-430
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• 2008

A new active vibration measurement system in electric power transmission line is presented, using in the nondestructive test. With a permanent magnet and a couple of coils, the system exerts impact force to a test object and in turn picks up the vibration of the object. The natural frequency with the amplitude obtained from the system are used as a basis for the detection of defects in the object. The system is controlled by an electronic device designed to facilitate the fully automated testing process with consistent repeatability and reliability which are essential to the nondestructive test. The system is expected to be applied to the wide area of defect detection including the classification of mechanical parts in production and inspection processes.

• Transactions of Materials Processing
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• v.13 no.7
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• pp.594-599
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• 2004

In the sheet metal forming operations, the strain measurement of sheet panel is an essential work which provides the formability information needed in die design, process design, and product inspection. To measure efficiently complex geometry strains, the 3-dimensional automative strain measurement system, which theoretically has a high accuracy but practically has about 3～5％ strain error, is often used. For eliminating the strain error resulted in measuring the strains of formed panels using an automated strain measurement system, the position error calibration method is suggested, which computes accurate strains using the grids with accurate nodal coordinates. The accurate nodal coordinates are calculated by adding the nodal coordinates measured by the measurement system and the position error found using the multiple regression method as a function of the main error parameters obtained from the analysis of strain error in a standard cube. For the verification, the strain distributions of square and dome cups obtained from the position error calibration method are compared with those provided by the finite element analysis and ASAME.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.1105-1106
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• 2019

고도성장 당시 건축되었던 사회기반시설들은 노후화로 인한 안전사고의 위험성이 부각되고 있다. 사회기반시설 중 교량의 경우 건축방식, 기후에 따른 안전점검 간 제약사항이 생긴다. 본 논문에서는 드론을 통해 점검이 필요한 교량을 촬영한다. 교량의 촬영 데이터를 정합 이미지로 생성하여 교량 내 유지보수를 위한 교량 모니터링 시스템을 제안한다.