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 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 Pixelated Carrier Phase-Shifting Shearography Using Spatiotemporal Low-Pass Filtering Algorithm

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5185
Author(s):  
Peizheng Yan ◽  
Xiangwei Liu ◽  
Shuangle Wu ◽  
Fangyuan Sun ◽  
Qihan Zhao ◽  
...  
Keyword(s):  
Carrier Phase ◽  
Speckle Noise ◽  
Phase Shifting ◽  
Destructive Testing ◽  
Full Field ◽  
Filtering Algorithm ◽  
Real Time Measurement ◽  
Low Pass ◽  
Carrier Phase Shifting ◽  
Non Destructive

Shearography has been widely used in non-destructive testing due to its advantages in providing full-field, high precision, real-time measurement. The study presents a pixelated carrier phase-shifting shearography using a pixelated micropolarizer array. Based on the shearography, a series of shearograms are captured and phase maps corresponding to deformation are measured dynamically and continuously. Using the proposed spatiotemporal filtering algorithm in the complex domain, the set of phase maps are simultaneously low-pass filtered in the spatial and temporal domains, resulting in better phase quality than spatial low-pass filtering. By accumulating the temporally adjacent phase, the phase corresponding to large deformation can be evaluated; thus, large deformations can be accurately measured and protected from speckle noise, allowing internal defects to be easily identified. The capability of the proposed shearography is described by theoretical discussions and experiments.

scholarly journals 3D Measurement Technology by Structured Light Using Stripe-Edge-Based Gray Code

2006 ◽  
Vol 48 ◽  
pp. 537-541 ◽  
Author(s):  
H B Wu ◽  
Y Chen ◽  
M Y Wu ◽  
C R Guan ◽  
X Y Yu
Keyword(s):  
Structured Light ◽  
Gray Code ◽  
Measurement Technology ◽  
3D Measurement ◽  
Edge Based

Full-field 3D measurement using multi-camera digital image correlation system

2013 ◽  
Vol 51 (9) ◽  
pp. 1044-1052 ◽  
Author(s):  
Fanxiu Chen ◽  
Xu Chen ◽  
Xin Xie ◽  
Xiu Feng ◽  
Lianxiang Yang
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
3D Measurement ◽  
Full Field ◽  
Correlation System

Precision Comparison of 3D Measurement System Based on Stereo Vision

2012 ◽  
Vol 542-543 ◽  
pp. 635-638
Author(s):  
Ke Zhang ◽  
Zhao Gao
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Quality Control ◽  
Stereo Vision ◽  
Measurement System ◽  
Bp Neural Network ◽  
Robot Vision ◽  
Measurement Technology ◽  
3D Measurement ◽  
3D Measurement System

The 3D measurement based on stereo vision, as a new measurement technology, has been widely used in reverse engineering, robot vision and quality control, etc. In this paper, the basic principle and method of calibrating 3D measurement system based on stereo vision respectively using genetic algorithm and neural network was introduced. Then the measurement system was calibrated and the precision of 3D measurement system was compared. The experimental results indicate that the method based on BP neural network can improve the precision of measurement better.

scholarly journals Strength Reliability of Micro Polycrystalline Silicon Structure

2007 ◽  
Vol 345-346 ◽  
pp. 777-780
Author(s):  
Shigeru Hamada ◽  
Kenji Hashizume
Keyword(s):  
Polycrystalline Silicon ◽  
Microelectromechanical Systems ◽  
Bending Strength ◽  
Chemical Vapor ◽  
Material Strength ◽  
Mems Devices ◽  
Bending Tests ◽  
Average Value ◽  
Micron Size ◽  
Mechanical Movement

In order to evaluate strength reliability of micron size polycrystalline silicon (poly-Si) structure, bending tests of cantilever beam and Weibull analysis are performed. Recently, the importance of microelectromechanical systems (MEMS) in society is increasing, and the number of production is also increasing. The MEMS devices, which contain mechanical movement, have to maintain their reliability in face of external shock, thermal stress and residual stress from manufacturing processes. In greeting the mass production era of the MEMS, in case the material strength design of MEMS is performed, required strength data is not average value but the variation, especially minimum value of the material. Micron size poly-Si structure is widely employed in the MEMS such as microsensor, switching device and so on. Then, in order to evaluate strength reliability of micron size poly-Si structure, tests and analysis are performed. The specimen is made by chemical vapor deposition (CVD) process and thickness is 3.5, 6.4 and 8.3 micrometer and the specimen has notch. The test specimen used for the test changed characteristics of (1) film thickness (2) stress concentration, and investigation about the influence each effects of the variation in a bending strength are discussed.

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