• Title/Summary/Keyword: Detection of defect

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The Development of Automatic Inspection System for Flaw Detection in Welding Pipe (배관용접부 결함검사 자동화 시스템 개발)

  • Yoon Sung-Un;Song Kyung-Seok;Cha Yong-Hun;Kim Jae-Yeol
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.2
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    • pp.87-92
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    • 2006
  • This paper supplements shortcoming of radioactivity check by detecting defect of SWP weld zone using ultrasonic wave. Manufacture 2 stage robot detection systems that can follow weld bead of SWP by method to detect weld defects of SWP that shape of weld bead is complex for this as quantitative. Also, through signal processing ultrasonic wave defect signal system of GUI environment that can grasp easily existence availability of defect because do videotex compose. Ultrasonic wave signal of weld defects develops artificial intelligence style sightseeing system to enhance pattern recognition of weld defects and the classification rate using neural net. Classification of weld defects that do fan Planar defect and that do volume defect of by classify.

A New Lighting System for the Inspection of Check Defect of CRT Panel (CRT 판넬의 첵 불량 검출을 위한 새로운 조명 시스템)

  • 차준혁;권인소;하종은
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.6
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    • pp.487-493
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    • 2004
  • In this Paper, we propose a lighting system for the stable detection of check defects of the CRT panel through the analysis of the lighting interaction between the lighting unit and the CRT panel. The check defect is very difficult to detect reliably because of its high sensitivity according to the direction of incident light. At first, we model the physical shape of check defects using SEM image. And then we apply physics based illumination model to investigate the optical characteristics of the check defect. Finally, we propose a lighting system for the stable detection of check defect. Experimental results show the feasibility of the proposed lighting system for check inspection.

A Sobel Operator Combined with Patch Statistics Algorithm for Fabric Defect Detection

  • Jiang, Jiein;Jin, Zilong;Wang, Boheng;Ma, Li;Cui, Yan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.2
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    • pp.687-701
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    • 2020
  • In the production of industrial fabric, it needs automatic real-time system to detect defects on the fabric for assuring the defect-free products flow to the market. At present, many visual-based methods are designed for detecting the fabric defects, but they usually lead to high false alarm. Base on this reason, we propose a Sobel operator combined with patch statistics (SOPS) algorithm for defects detection. First, we describe the defect detection model. mean filter is applied to preprocess the acquired image. Then, Sobel operator (SO) is applied to deal with the defect image, and we can get a coarse binary image. Finally, the binary image can be divided into many patches. For a given patch, a threshold is used to decide whether the patch is defect-free or not. Finally, a new image will be reconstructed, and we did a loop for the reconstructed image to suppress defects noise. Experiments show that the proposed SOPS algorithm is effective.

A Welding Defect Inspection using an Ultrasound Excited Thermography (초음파 서모그라피를 이용한 용접 결함 검사)

  • Jo Jae-Wan;Jeong Jin-Man;Choi Yeong-Su;Jeong Seung-Ho;Jeong Hyeon-Gyu
    • Proceedings of the KWS Conference
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    • 2006.05a
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    • pp.148-150
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    • 2006
  • In this paper, the applicability of an UET(ultrasound excited thermography) for a defect detection of the welded receptacle is described. An UET(ultrasound excited thermography) is a defect-selective and fast imaging tool for damage detection. A high power ultrasound-excited vibration energy with pulse durations of 280ms is injected into the outer surface of the welded receptacle made of Al material. An ultrasound vibration energy sent into the welded receptacle propagate inside the sample until they are converted into the heat in the vicinity of the defect. The injection of the ultrasound excited vibration energy results in heat generation so that the defect is turned into a local thermal wave transmitter. Its local heat emission is monitored by the thermal infrared camera. And they are processed by the image recording system. Measurement was performed on aluminum receptacle welded by using Nd:YAG laser. The observed thermal image revealed two area of defects along the welded seam.

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Deep Learning Models for Fabric Image Defect Detection: Experiments with Transformer-based Image Segmentation Models (직물 이미지 결함 탐지를 위한 딥러닝 기술 연구: 트랜스포머 기반 이미지 세그멘테이션 모델 실험)

  • Lee, Hyun Sang;Ha, Sung Ho;Oh, Se Hwan
    • The Journal of Information Systems
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    • v.32 no.4
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    • pp.149-162
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    • 2023
  • Purpose In the textile industry, fabric defects significantly impact product quality and consumer satisfaction. This research seeks to enhance defect detection by developing a transformer-based deep learning image segmentation model for learning high-dimensional image features, overcoming the limitations of traditional image classification methods. Design/methodology/approach This study utilizes the ZJU-Leaper dataset to develop a model for detecting defects in fabrics. The ZJU-Leaper dataset includes defects such as presses, stains, warps, and scratches across various fabric patterns. The dataset was built using the defect labeling and image files from ZJU-Leaper, and experiments were conducted with deep learning image segmentation models including Deeplabv3, SegformerB0, SegformerB1, and Dinov2. Findings The experimental results of this study indicate that the SegformerB1 model achieved the highest performance with an mIOU of 83.61% and a Pixel F1 Score of 81.84%. The SegformerB1 model excelled in sensitivity for detecting fabric defect areas compared to other models. Detailed analysis of its inferences showed accurate predictions of diverse defects, such as stains and fine scratches, within intricated fabric designs.

The ISO/TS16949 the research regarding the application instance of the development technique for a APQP zero defect attainment (ISO/TS16949 APQP Zero Defect 달성을 위한 개발기법의 적용사례에 관한 연구)

  • Moon, Chan-Oh
    • Management & Information Systems Review
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    • v.22
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    • pp.211-229
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    • 2007
  • The ISO/TS16949 APQP goal of defect prevention and decrease of spread waste, is the customer satisfaction which leads a continuous improvement and profit creation. The quality expense where the most is caused by but with increase of production initial quality problem occurrence is increasing to is actuality. Like this confirmation amendment. with the problem which is forecast in the place development at the initial stage which it does completeness it does not confront not to be able, production phase to be imminent, the problem accumulates and it talks the development shedding of which occurs. In opposition, prediction confrontation. is forecast in development early stage to and it is a structure which does not occur a problem to production early stage. Like this development is a possibility of accomplishing competitive company from production phase. Which attains an goal of, chance cause it leads a APQP activity (common cause) with special cause prevention & detection the connection characteristic of the focus technique against a interaction is important. And the customer requirement satisfaction and must convert a APQP goal of attainment at the key characteristics action step. (1) The Prevention - with Design FMEA application prevention of the present design management/detection, (2) the Detection (prevention/detection) - with Process FMEA application prevention of the present process control/detection, (3) Special Cause - statistical process control (SPC) 4M cause spread removal, (4) Common Cause - statistical process control (SPC) the nothing zero defect which leads the continuous improvement back of spread with application it will be able to attain with application.

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Application Defects Detection in the Small-Bore Pipe Using Infrared Thermography Technique (적외선열화상 카메라를 이용한 원전 소구경 감육배관의 결함 검출)

  • Yun, Kyung-Won;Kim, Dong-Lyul;Jung, Hyun-Chul;Hong, Dong-Pyo;Kim, Kyeong-Suk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.33 no.1
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    • pp.34-39
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    • 2013
  • In the advanced research deducted infrared thermography (IRT) test using 4 inch pipe with artificial wall-thinning defect to measure on the wall-thinned nuclear pipe components. This study conducted for defect detection condition of nuclear small-bore pipe research using deducted condition in the advanced research. Defect process is processed by change for defect length, circumferential direction angle, wall-thinning depth. In the used equipment IR camera and two halogen lamps, whose full power capacitany is 1 kW, halogen lamps and Target pipe experiment performed to the distance of the changed 1 m, 1.5 m, 2 m. To analysis of the experimental results ensure for the temperature distribution data, by this data measure for defect length. artificial defect of 4 inch pipe is high reliability in the 2 m, but small-bore pipe is in the 1.5 m from the defect clearly was detected.

Wheel tread defect detection for high-speed trains using FBG-based online monitoring techniques

  • Liu, Xiao-Zhou;Ni, Yi-Qing
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.687-694
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    • 2018
  • The problem of wheel tread defects has become a major challenge for the health management of high-speed rail as a wheel defect with small radius deviation may suffice to give rise to severe damage on both the train bogie components and the track structure when a train runs at high speeds. It is thus highly desirable to detect the defects soon after their occurrences and then conduct wheel turning for the defective wheelsets. Online wheel condition monitoring using wheel impact load detector (WILD) can be an effective solution, since it can assess the wheel condition and detect potential defects during train passage. This study aims to develop an FBG-based track-side wheel condition monitoring method for the detection of wheel tread defects. The track-side sensing system uses two FBG strain gauge arrays mounted on the rail foot, measuring the dynamic strains of the paired rails excited by passing wheelsets. Each FBG array has a length of about 3 m, slightly longer than the wheel circumference to ensure a full coverage for the detection of any potential defect on the tread. A defect detection algorithm is developed for using the online-monitored rail responses to identify the potential wheel tread defects. This algorithm consists of three steps: 1) strain data pre-processing by using a data smoothing technique to remove the trends; 2) diagnosis of novel responses by outlier analysis for the normalized data; and 3) local defect identification by a refined analysis on the novel responses extracted in Step 2. To verify the proposed method, a field test was conducted using a test train incorporating defective wheels. The train ran at different speeds on an instrumented track with the purpose of wheel condition monitoring. By using the proposed method to process the monitoring data, all the defects were identified and the results agreed well with those from the static inspection of the wheelsets in the depot. A comparison is also drawn for the detection accuracy under different running speeds of the test train, and the results show that the proposed method can achieve a satisfactory accuracy in wheel defect detection when the train runs at a speed higher than 30 kph. Some minor defects with a depth of 0.05 mm~0.06 mm are also successfully detected.

Defect Detection of Ceramic Heating Plate Using Ultrasound Pulse Thermography (초음파 펄스 서모그라피를 이용한 세라믹 전열 판의 결함 검출)

  • Cho, Jai-Wan;Seo, Yong-Chil;Jung, Seung-Ho;Kim, Seung-Ho;Jung, Hyun-Kyu
    • Journal of the Korean Ceramic Society
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    • v.43 no.4 s.287
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    • pp.259-263
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    • 2006
  • The applicability of UPT (Ultrasound Pulse Thermography) for real-time defect detection of the ceramic heating plate is described. The ceramic heating plate with superior insulation and high radiation is used to control the water temperature in underwater environment. The underwater temperature control system can be damaged owing to the short circuit, which resulted from the defect of the ceramic heating plate. A high power ultrasonic energy with pulse duration of 280 ms was injected into the ceramic heating plate in the vertical direction. The ultrasound excited vibration energy sent into the component propagate inside the sample until they were converted to the heat in the vicinity of the defect. Therefore, an injection of the ultrasound pulse wave which results in heat generation, turns the defect into a local thermal wave transmitter. Its local emission is monitored and recorded via the thermal infrared camera at the surface which is processed by image recording system. Measurements were Performed on 4 kinds of samples, composed of 3 intact plates and the defect plate. The observed thermal image revealed two area of crack in the defective ceramic heating plate.

Automatic Defect Inspection with Adaptive Binarization and Bresenham's Algorithm for Spectacle Lens Products (적응적 이진화 기법과 Bresenham's algorithm을 이용한 안경 렌즈 제품의 자동 흠집 검출)

  • Kim, Kwang Baek;Song, Dong Heon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.7
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    • pp.1429-1434
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    • 2017
  • In automatic defect detection problem for spectacle lenses, it is important to extract lens area accurately. Many existing detection methods fail to do it due to insufficient minute noise removal. In this paper, we propose an automatic defect detection method using Bresenham algorithm and adaptive binarization strategy. After usual average binarization, we apply Bresenham algorithm that has the power in extracting ellipse shape from image. Then, adaptive binarization strategy is applied to the critical minute noise removal inside the lens area. After noise removal, We can also compute the influence factor of the defect based on the fuzzy logic with two membership functions such as the size of the defect and the distance of the defect from the center of the lens. In experiment, our method successfully extracts defects in 10 out of 12 example images that include CHEMI, MID, HL, HM type lenses.