Three-dimensional inspection system

1987 ◽  
Vol 9 (4) ◽  
pp. 234
Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5136
Author(s):  
Xiaoxin Fang ◽  
Qiwu Luo ◽  
Bingxing Zhou ◽  
Congcong Li ◽  
Lu Tian

The computer-vision-based surface defect detection of metal planar materials is a research hotspot in the field of metallurgical industry. The high standard of planar surface quality in the metal manufacturing industry requires that the performance of an automated visual inspection system and its algorithms are constantly improved. This paper attempts to present a comprehensive survey on both two-dimensional and three-dimensional surface defect detection technologies based on reviewing over 160 publications for some typical metal planar material products of steel, aluminum, copper plates and strips. According to the algorithm properties as well as the image features, the existing two-dimensional methodologies are categorized into four groups: statistical, spectral, model, and machine learning-based methods. On the basis of three-dimensional data acquisition, the three-dimensional technologies are divided into stereoscopic vision, photometric stereo, laser scanner, and structured light measurement methods. These classical algorithms and emerging methods are introduced, analyzed, and compared in this review. Finally, the remaining challenges and future research trends of visual defect detection are discussed and forecasted at an abstract level.


1990 ◽  
Vol 217 ◽  
Author(s):  
J.H. Kinney ◽  
M.C. Nichols ◽  
U. Bonse ◽  
S.R. Stock ◽  
T.M. Breunig ◽  
...  

ABSTRACTA technique for nondestructively imaging microstructures of materials in situ, especially a technique capable of delineating the time evolution of chemical changes or damage, will greatly benefit studies of materials processing and failure. X-ray tomographic microscopy (XTM) is a high resolution, three-dimensional inspection method which is capable of imaging composite materials microstructures with a resolution of a few micrometers. Because XTM is nondestructive, it will be possible to examine materials under load or during processing, and obtain three-dimensional images of fiber positions, microcracks, and pores. This will allow direct imaging of microstructural evolution, and will provide time-dependent data for comparison to fracture mechanics and processing models.


2001 ◽  
Author(s):  
Ravil M. Galiulin ◽  
Barry G. Ilyasov ◽  
Rishat M. Galiulin ◽  
J. M. Bakirov ◽  
D. R. Bogdanov ◽  
...  

2020 ◽  
Author(s):  
Taku Sakamoto ◽  
Ichiro Oda ◽  
Takuma Okamura ◽  
Hourin Cho ◽  
Satoru Nonaka ◽  
...  

Abstract Accurate measurement of the distance between any two points under endoscopic examination of the gastrointestinal tract is difficult due to the fisheye lens currently used on endoscopes. To overcome this issue, we developed a three-dimensional visual inspection system that incorporates a phase-shift method for direct measurement of a three-dimensional shape. Projection of a striped pattern is used to enable three-dimensional renderings of a surface using an industrial camera. We evaluated the accuracy of measurement relative to that of reference measurements obtained using a measurement microscope, for three-dimensional shapes on a plane and curved surface. For 60 regions of interests, with various configurations of the reference locations relative to the camera, the measurement error for our system was <0.1 mm on the plane grid and <0.5 mm on the curved surface. The accuracy of our novel three-dimensional visual inspection system could improve determination of the size of lesions with different shapes, flat or depressed, regardless of the curved surface of the gastrointestinal tract.


2013 ◽  
Vol 5 ◽  
pp. 620786 ◽  
Author(s):  
Roberto Marani ◽  
Massimiliano Nitti ◽  
Grazia Cicirelli ◽  
Tiziana D'Orazio ◽  
Ettore Stella

Author(s):  
Hiroshi Sato ◽  
Takayuki Hamajima ◽  
Masahiro Katayama ◽  
Yasuhisa Kanamaru

Quality requirements for girth welded joints in gas pipelines necessitate adequate penetration to the inner surface and no harmful defects. Toho Gas has completed development of the world’s first inspection system applying the ultrasonic synthetic aperture method for welds in steel pipes used to carry gas (external diameter 200mm, pipe wall thickness 5.8mm). In recent years, ultrasonic phased-array technology and ultrasonic TOFD methods etc. have attracted attention. However, the ultrasonic synthetic aperture method is an imaging technology that is superior to these, as it can synthesize several thousands of wave form data at high speed, its image clarity is the best in the world. The four features of the system are (1) the ability to provide an image of the interior of a weld, (2) the ability to quantity incomplete root bead penetration, (3) automatic high speed collection of data, and (4) data base management capability. The ultrasonic synthetic aperture method simplifies defect judgments because it does not require that operators possess special qualifications and training. It can produce three-dimensional high picture quality data. It can be handled easily at work sites because it is portable. This report describes the ultrasonic inspection system development process and the results of trial inspections.


2011 ◽  
Vol 2-3 ◽  
pp. 463-468
Author(s):  
Ji Gang Wu ◽  
Kuan Fang He ◽  
Bin Qin

According to the two indices of inspection accuracy and inspection speed, a planar contour primitive recognition method of thin sheet part dimensional inspection system based on curvature and HOUGH transform is proposed. A contour point classification algorithm based on neighborhood values is developed, and a curvature threshold method is selected to filter the contour points, and a projection height method is selected to distinguish the property of the primitive and classify the contour points, and the straight line primitive and arc primitive segmentation and merging algorithms are constructed respectively by HOUGH transform. The inspection accuracy and inspection speed of the proposed method are compared and analyzed by contrast experiments between the proposed method and four dominant point detection methods such as Chung & Tsai method and so on. The dominant point detection ability of the proposed method is tested by a simulation planar contour which includes all kinds of dominant points. The experimental results indicate that the proposed method can recognize primitives exactly, the inspection speed is fast and the universality is good.


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