Application of full-field non-contact measurement technology to clarification of deterioration mechanism on constructional material

2012 ◽  
pp. 2182-2189
Author(s):  
H Goda ◽  
M Hibino ◽  
Y Kawabata ◽  
M Uchino ◽  
H Matsuda
Keyword(s):  
Constructional Material ◽  
Measurement Technology ◽  
Full Field ◽  
Contact Measurement ◽  
Deterioration Mechanism

scholarly journals Vision-based Deformation Measurement for Pile-soil Testing

2019 ◽  
Vol 275 ◽  
pp. 03009
Author(s):  
Kun Zhou ◽  
Linhua Chen ◽  
Shanshan Yu
Keyword(s):  
Measurement Method ◽  
Optical Measurement ◽  
High Sensitivity ◽  
Steel Tube ◽  
Image Features ◽  
Deformation Measurement ◽  
Measurement Technology ◽  
Full Field ◽  
Progressive Development ◽  
Point Tracking

Image measurement technology has been widely used in monitoring the deformation of the soil field around the pile with its advantages of no damage, no contact, full-field measurement, no added quality and high sensitivity. But there are few researches on image-based bearing deformation measurement of the pile. Through an indoor pile-soil semi-model test, the rigid body displacement and load-bearing deformation of a new type of prefabricated steel tube pile foundation under horizontal load was measured based on image features. In this study, the concept of optical extensometer is first applied to the measurement of local average strain of a non-uniform deformed structure. Based on an improved feature point tracking algorithm SURF-BRISK, non-contact measurement of tiny strain of pile body is realized. In addition, based on DIC technology, this study also obtained the progressive development of displacement field of soil around pile. The above work fully reflects the non-contact convenience and full-field richness of the optical measurement method compared with the traditional measurement method.

scholarly journals Multiple Laser Stripe Scanning Profilometry Based on Microelectromechanical Systems Scanning Mirror Projection

Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 57 ◽  
Author(s):  
Gailing Hu ◽  
Xiang Zhou ◽  
Guanliang Zhang ◽  
Chunwei Zhang ◽  
Dong Li ◽  
...  
Keyword(s):  
Microelectromechanical Systems ◽  
Speckle Noise ◽  
Measurement Technology ◽  
3D Measurement ◽  
High Quality ◽  
Full Field ◽  
Scanning Mirror ◽  
Laser Stripe ◽  
Measurement Efficiency ◽  
Mechanical Movement

In traditional laser-based 3D measurement technology, the width of the laser stripe is uncontrollable and uneven. In addition, speckle noise in the image and the noise caused by mechanical movement may reduce the accuracy of the scanning results. This work proposes a new multiple laser stripe scanning profilometry (MLSSP) based on microelectromechanical systems (MEMS) scanning mirror which can project high quality movable laser stripe. It can implement full-field scanning in a short time and does not need to move the measured object or camera. Compared with the traditional laser stripe, the brightness, width and position of the new multiple laser stripes projected by MEMS scanning mirror can be controlled by programming. In addition, the new laser strip can generate high-quality images and the noise caused by mechanical movement is completely eliminated. The experimental results show that the speckle noise is less and the light intensity distribution is more even. Furthermore, the number of pictures needed to be captured is significantly reduced to 1 / N ( N is the number of multiple laser stripes projected by MEMS scanning mirror) and the measurement efficiency is increased by N times, improving the efficiency and accuracy of 3D measurement.

scholarly journals Three-Dimensional Morphology and Size Measurement of High-Temperature Metal Components Based on Machine Vision Technology: A Review

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4680
Author(s):  
Xin Wen ◽  
Jingpeng Wang ◽  
Guangyu Zhang ◽  
Lianqiang Niu
Keyword(s):  
High Temperature ◽  
Machine Vision ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Measurement Technology ◽  
Metal Component ◽  
Contact Measurement ◽  
Size And Morphology ◽  
Close Distance ◽  
Very High

The three-dimensional (3D) size and morphology of high-temperature metal components need to be measured in real time during manufacturing processes, such as forging and rolling. Since the surface temperature of a metal component is very high during the forming and manufacturing process, manually measuring the size of a metal component at a close distance is difficult; hence, a non-contact measurement technology is required to complete the measurement. Recently, machine vision technology has been developed, which is a non-contact measurement technology that only needs to capture multiple images of a measured object to obtain the 3D size and morphology information, and this technology can be used in some extreme conditions. Machine vision technology has been widely used in industrial, agricultural, military and other fields, especially fields involving various high-temperature metal components. This paper provides a comprehensive review of the application of machine vision technology in measuring the 3D size and morphology of high-temperature metal components. Furthermore, according to the principle and method of measuring equipment structures, this review highlights two aspects in detail: laser scanning measurement and multi-view stereo vision technology. Special attention is paid to each method through comparisons and analyses to provide essential technical references for subsequent researchers.

Measuring Die Tilt Using Shadow Moiré Optical Measurements; New Techniques for Discontinuous and Semi-Reflective Surfaces

2016 ◽  
Vol 2016 (1) ◽  
pp. 000612-000617
Author(s):  
Neil Hubble
Keyword(s):  
High Speed ◽  
Flip Chip ◽  
Elevated Temperatures ◽  
Semiconductor Industry ◽  
Measurement Techniques ◽  
Optical Measurements ◽  
Measurement Technology ◽  
Full Field ◽  
Shadow Moire ◽  
Shadow Moiré

Abstract When dealing with production of Flip Chip Packages in semiconductor packaging, the angle between the die and package substrate is critical for maintaining product yield and reliability. Current outgoing quality checks for die tilt can be time consuming to measure heights via point to point measurement techniques. Existing die tilt measurement approaches can also have reproducibility issues from user to user. Shadow moiré technology is a full field optical inspection technique commonly used for flatness characterization in the semiconductor industry, particularly at elevated temperatures. Two limitations to shadow moiré apply when discussing outgoing QC of die tilt: 1) shadow moiré requires a diffuse reflective surface for measurement; 2) shadow moiré is unable to measure sudden step heights. This paper discusses applications techniques and real world examples to overcome or mitigate the limitations of shadow moiré technology and use this full field and high speed measurement technology to measure die tilt. Using shadow moiré for this measurement technology can reduce measurement and user time as well as improve consistency of measurements from user to user. As shadow moiré tools are often used for at temperature flatness measurements, this added application can reduce the number of different measurement tools needed in QA labs.

scholarly journals Design and Analysis of High-Accuracy Telecentric Surface Reconstruction System Based on Line Laser

2021 ◽  
Vol 11 (2) ◽  
pp. 488
Author(s):  
Linshen Yao ◽  
Haibo Liu
Keyword(s):  
Computer Vision ◽  
Surface Reconstruction ◽  
High Accuracy ◽  
Measurement Technology ◽  
Single Camera ◽  
One Dimensional ◽  
Contact Measurement ◽  
Laser Plane ◽  
On Line ◽  
Telecentric Lens

Non-contact measurement technology based on triangulation with cameras is extensively applied to the development of computer vision. However, the accuracy of the technology is generally not satisfactory enough. The application of telecentric lenses can significantly improve the accuracy, but the view of telecentric lenses is limited due to their structure. To address these challenges, a telecentric surface reconstruction system is designed for surface detection, which consists of a single camera with a telecentric lens, line laser generator and one-dimensional displacement platform. The designed system can reconstruct the surface with high accuracy. The measured region is expanded with the used of the displacement platform. To achieve high-accuracy surface reconstruction, we propose a method based on a checkerboard to calibrate the designed system, including line laser plane and motor direction of the displacement platform. Based on the calibrated system, the object under the line laser is measured, and the results of lines are assembled to make the final surface reconstruction. The results show that the designed system can reconstruct a region of 20×40 mm2, up to the accuracy of micron order.

Sign in / Sign up

Export Citation Format

Share Document