• 한국산업정보학회논문지
• /
• 제12권3호
• /
• pp.116-123
• /
• 2007

평판 디스플레이 부품시장 및 관련 개발장비 시장의 확대에 따른 백라이트 생산업체들의 수가 크게 증가했음에도 불구하고 LCD부품의 색재현에 좋지 못한 영향을 끼치는 백라이트 표면의 이물이나 백점, 스크래치와 같은 결함검사는 여전히 작업자의 육안에 의존하고 있는 실정이다. 그러나 육안검사에서는 작업자의 신체상태나 작업능력에 따라 검사정밀도와 검사속도 등이 달라질 수 있기 때문에 검사품질의 일관성을 유지시키기 어려울 뿐만 아니라 전체 공정의 효율도 저하시킨다. 본 연구에서는 백라이트 표시면치육안 결함검사를 자동화할 수 있는 백라이트 표면결함 검사시스템 개발에 관해 연구하였으며, 이를 위해 컴퓨터비젼시스템을 구성하고 검사공정을 위한 운용프로그램과 검사작업에 필요한 작업자 인터페이스 그리고 결함정보 추출을 위한 영상처리모듈을 구현하였다 또한, 이진화된 결함화소들 간의 연결구조로부터 고립된 결함영역을 추출하기 위해 레이블 테이블과 결함 인덱스를 사용한 레이블링 알고리즘을 고안하였다. 본 검사시스템의 검사성능을 평가하기 위한 실험결과, 시각적으로 식별가능 한 모든 결함영역이 검사시스템에 의해 검출됨에 따라 본 연구의 검사시스템이 작업자의 육안검사를 대체하기에 만족할만한 성능을 보임을 착인 할 수 있었다.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2000년도 추계종합학술대회
• /
• pp.590-594
• /
• 2000

피혁 제품의 품질을 결정함에 있어 제일 중요한 요인은 눈에 보이는 표면상태이다 지금까지는 피혁공장에서 대부분의 피혁을 육안으로 선별하여 오고 있는데 이러한 방법은 등급을 구분하는데 많은 노동력과 시간이 소모되고, 일관성이 부족할 뿐만 아니라 미세한 결함이나 정밀한 치수를 감지할 수가 없어 그 등급의 품질에 문제가 발생한다. 이런 문제를 해결하기 위해 본 논문에서는 실시간 영상처리와 A.I를 이용하여 피혁 자동 등급 선별 시스템을 설계하고자 한다. 제안한 선별 시스템의 설계는 세계 피혁업계와 차별을 기하고 검사시간을 단축하여 생산 효율성을 증대하며, 등급의 표준화 및 품질의 고급화를 도모할 수 있다.

• 제어로봇시스템학회논문지
• /
• 제4권3호
• /
• pp.384-391
• /
• 1998

When a device is mounted on the PCB, it is impossible to have zero defects due to many unpredictable problems. Among these problems, devices with bent corner leads due to mis-handling and which are not placed at a given point measured along the axis are principal problem in SMT(Surface Mounting Technology). It is obvious that given the complexity of the inspection task, the efficiency of a human inspection is questionable. Thus, new technologies for inspection of SMD(Surface Mounting Device) should be explored. An example of such technologies is the Automated Visual Inspection(AVI), wherein the vision system plays a key role to correct this problem. In implementing vision system, high-speed and high-precision are indispensable for practical purposes. In this paper, a new algorithm based on the Radon transform which uses a projection technique to inspect the FIC(Flat Integrated Circuit) device is proposed. The proposed algorithm is compared with other algorithms by measuring the position error(center and angle) and the processing time for the device image, characterized by line scan camera.

• 한국정보통신학회논문지
• /
• 제19권7호
• /
• pp.1737-1742
• /
• 2015

물품 검사를 위한 산업현장에서는 물품의 표면뿐만 아니라 내부 부품결함 검사 또한 필요하다. 일반적으로 생산 공정에서의 물품 검사로 광학 검사를 많이 이용한다. 하지만 이는 표면상의 결함만을 검사할 뿐 물품 내부의 검사를 수행하기는 어렵다. 이러한 제한점을 극복하기 위해 광학 장치 대신 휴대용 X-선 DR 영상 획득 장치를 이용하여 영상을 실시간으로 얻는 동시에 제품 불량을 판별할 수 있는 시스템을 개발하였다. X-선 영상을 얻은 후 머신영상 처리를 통해 설정한 기준 값에 오차범위를 허용하면 통과, 그렇지 않으면 불량으로 인식되도록 시스템을 개발하였다. 또한, 물품의 불량 유무 결과와 그 수치는 사용자가 저장할 수 있도록 하였다.

• 한국도로학회논문집
• /
• 제19권2호
• /
• pp.103-112
• /
• 2017

PURPOSES : In this study, field performance evaluation of crack treatment of pavement and the feasibility of surface treatment of pavement are presented. The performance and cost of preventive maintenance methods have been previously verified, and the methods are being used in many developed countries and cities. However, the performance and cost of the system have not been verified in domestic, field applications. Therefore, in order to improve performance, the field performance is evaluated, and a reasonable cost is proposed. METHODS : Visual Inspection was conducted to evaluate the field application and performance of the preventive maintenance method. In addition, the PCI index was calculated from the results of visual inspection of the application area of the surface treatment method, and the performance life of each method was predicted. For the economic evaluation, life cycle cost analysis was performed using the life cycle cost analysis program. RESULTS :In order to evaluate and quantify the field performance of crack repair material, the residue condition of the pavement surface after crack treatment, rather than the performance of the material, is evaluated. In addition, the crack resistance and performance life of surface treatment methods are evaluated. The cost of currently available treatment methods are compared to the common pavement cut and overlay method, and it is determined that the preventive method is not economical based on life cycle cost analysis. CONCLUSIONS :Because of the characteristics of cracking, it is necessary to conduct the evaluation of currently applied methods and the analysis of the cause of damage, by visual inspection. Moreover, in order to evaluate the performance and economic suitability of the currently applied surface treatment methods, it is necessary to acquire information on application sections by monitoring their long-term conditions and performance.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.295-298
• /
• 2000

In this research, a novel sampling strategy for a CMM to inspect freeform surfaces is proposed. Unlike primitive surfaces, it is not easy to determine the number of sampling points and their locations for inspecting freeform surfaces. Since a CMM operates with slower speed in measurement than optical measuring devices, it is important to optimize the number and the locations of sampling points in the inspection process. When a complete inspection of a surface is required, it becomes more critical. Among various factors to cause shape errors of a final product, curvature characteristic is essential due to its effect such as stair-step errors in rapid prototyping and interpolation errors in NC tool paths generation. Shape errors are defined in terms of the average and standard deviation of differences between an original model and a produced part. Proposed algorithms determine the locations of sampling points by analyzing curvature distribution of a given surface. Based on the curvature distribution, a surface area is divided into several sub-areas. In each sub-area, sampling points are located as further as possible. The optimal number of sub-areas. In each sub-area, sampling points are located as further as possible. The optimal number os sub-areas is determined by estimating the average of curvatures. Finally, the proposed method is applied to several surfaces that have shape errors for verification.

• 융복합기술연구소 논문집
• /
• 제6권1호
• /
• pp.23-26
• /
• 2016

DC motor shafts have several defects such as double cut, deep scratch on surface, and defects in diameter and length. The deep scratches are due to collision among the other shafts. So the scratches are long and thin but their orientations are random. If the smallest enclosing box, i.e. oriented bounding box for a detective point group is found, then the size of the corresponding defect can be modeled as its diagonal length. This paper proposes an suface inspection algorithm for the DC motor shaft using the oriented bounding box. To evaluate the proposed algorithm, a test bed is made with a line scan CCD camera (4096 pixels/line) and two rollers mechanism to rotate the shaft. The experimental result on a pre-processed image with contrast streching algorithm, shows that the proposed algorithm sucessfully finds 150 surface defects and its computation time (0.291 msec) is enough fast for the requirement (4 seconds).

• 제어로봇시스템학회논문지
• /
• 제21권8호
• /
• pp.788-793
• /
• 2015

This paper proposes a path planning algorithm to reduce the inspection time of AOI (Automatic Optical Inspection) machines for SMT (Surface Mount Technology) in-line system. Since the field-of-view of the camera attached at the machine is much less than the entire inspection region of board, the inspection region should be clustered to many groups. The image acquisition time depends on the number of groups, and camera moving time depends on the sequence of visiting the groups. The acquired image is processed while the camera moves to the next position, but it may be delayed if the group includes many components to be inspected. The inspection delay has influence on the overall job time of the machine. In this paper, we newly considers the inspection delay time for path planning of the inspection machine. The unified approach using genetic algorithm is applied to generates the groups and visiting sequence simultaneously. The chromosome, crossover operator, and mutation operator is proposed to develop the genetic algorithm. The experimental results are presented to verify the usefulness of the proposed method.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.36-39
• /
• 1997

In this paper, we described an approach to design of precision optical system for visual inspection of solder joint defects of SMC(surface mount components) on PCBs(Printed Circuit Board). The illumination system, consisting of three tiered LED lamps and one main camera and four side view camera, is implemented to generated iso-contour on the solder joint according to gradient of the soldered surface. We analyze LED design parameter such as incident angle, diameter of LED ring, and so on to acquire uniform illumination.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.325-327
• /
• 2004

Novel surface profiler system for inspection of the display components is demonstrated In the case of the liquid crystal display, for example, not only the flatness of the alignment film but also the quality of rubbing can be inspected. Furthermore, the shape of the component such as the color filter, electrode and mirror can be inspected without removing each component.