Equivalent wavelength self-mixing interferometry for displacement measurement

2016 ◽  
Vol 55 (25) ◽  
pp. 7120 ◽  
Author(s):  
Zhen Huang ◽  
Chengwei Li ◽  
Songquan Li ◽  
Dongyu Li
Keyword(s):  
Displacement Measurement ◽  
Equivalent Wavelength

Laser displacement measurement using intensity modulation with a phase-modulated radio-frequency signal

2020 ◽  
Vol 14 (1) ◽  
pp. 012004
Author(s):  
Yosuke Tanaka ◽  
Kyosuke Yamaguchi ◽  
Kenta Yamamoto ◽  
Yoshiki Yamada
Keyword(s):  
Radio Frequency ◽  
Intensity Modulation ◽  
Displacement Measurement ◽  
Frequency Signal ◽  
Radio Frequency Signal

A Design of High-Accuracy Displacement Measurement Instrument from Principles of Optics

2012 ◽  
Vol 170-173 ◽  
pp. 2924-2928
Author(s):  
Sheng Biao Chen ◽  
Yun Zhi Tan
Keyword(s):  
Measurement Instrument ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Total Reflection ◽  
Displacement Measurement ◽  
New Method ◽  
Water Volume ◽  
Water Drainage ◽  
Accuracy Of Measurement ◽  
Better Than

In order to measure the water drainage volume in soil mechanical tests accurately, it develop a new method which is based on principles of optics. And from both physical and mathematic aspects, it deduces the mathematic relationship between micro change in displacement and the increment projected on screen. The result shows that total reflection condition is better than refraction condition. What’s more, the screen could show the water volume micro variation clearly, so it can improve the accuracy of measurement.

scholarly journals Integrated, Speckle-Based Displacement Measurement for Lateral Scanning White Light Interferometry

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2486
Author(s):  
Gert Behrends ◽  
Dirk Stöbener ◽  
Andreas Fischer
Keyword(s):  
White Light ◽  
Lateral Displacement ◽  
Displacement Measurement ◽  
Accurate Information ◽  
White Light Interferometry ◽  
Fully Integrated ◽  
Speckle Correlation ◽  
Dsc Measurements ◽  
Scanning White Light Interferometry ◽  
The Impact

Lateral scanning white light interferometry (LSWLI) is a promising technique for high-resolution topography measurements on moving surfaces. To achieve resolutions typically associated with white light interferometry, accurate information on the lateral displacement of the measured surface is essential. Since the uncertainty requirement for a respective displacement measurement is currently not known, Monte Carlo simulations of LSWLI measurements are carried out at first to assess the impact of the displacement uncertainty on the topography measurement. The simulation shows that the uncertainty of the displacement measurement has a larger influence on the total height uncertainty than the uncertainty of the displacing motion itself. Secondly, a sufficiently precise displacement measurement by means of digital speckle correlation (DSC) is proposed that is fully integrated into the field of view of the interferometer. In contrast to externally applied displacement measurement systems, the integrated combination of DSC with LSWLI needs no synchronization and calibration, and it is applicable for translatory as well as rotatory scans. To demonstrate the findings, an LSWLI setup with integrated DSC measurements is realized and tested on a rotating cylindrical object with a surface made of a linear encoder strip.

A low-finesse all-fiber sinusoidal phase modulation interferometer for displacement measurement

2021 ◽  
pp. 126997
Author(s):  
Jin Tao ◽  
Wei Wang ◽  
Lars Daul ◽  
Ludger Koenders ◽  
Wenmei Hou
Keyword(s):  
Phase Modulation ◽  
Displacement Measurement

scholarly journals Structural Damage Identification Based on Integrated Utilization of Inverse Finite Element Method and Pseudo-Excitation Approach

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 606
Author(s):  
Tengteng Li ◽  
Maosen Cao ◽  
Jianle Li ◽  
Lei Yang ◽  
Hao Xu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Damage ◽  
Damage Identification ◽  
Displacement Measurement ◽  
Engineering Practice ◽  
Position Measurement ◽  
Inverse Finite Element Method ◽  
Pseudo Excitation ◽  
Element Method

The attempt to integrate the applications of conventional structural deformation reconstruction strategies and vibration-based damage identification methods is made in this study, where, more specifically, the inverse finite element method (iFEM) and pseudo-excitation approach (PE) are combined for the first time, to give rise to a novel structural health monitoring (SHM) framework showing various advantages, particularly in aspects of enhanced adaptability and robustness. As the key component of the method, the inverse finite element method (iFEM) enables precise reconstruction of vibration displacements based on measured dynamic strains, which, as compared to displacement measurement, is much more adaptable to existing on-board SHM systems in engineering practice. The PE, on the other hand, is applied subsequently, relying on the reconstructed displacements for the identification of structural damage. Delamination zones in a carbon fibre reinforced plastic (CFRP) laminate are identified using the developed method. As demonstrated by the damage detection results, the iFEM-PE method possesses apparently improved accuracy and significantly enhanced noise immunity compared to the original PE approach depending on displacement measurement. Extensive parametric study is conducted to discuss the influence of a variety of factors on the effectiveness and accuracy of damage identification, including the influence of damage size and position, measurement density, sensor layout, vibration frequency and noise level. It is found that different factors are highly correlated and thus should be considered comprehensively to achieve optimal detection results. The application of the iFEM-PE method is extended to better adapt to the structural operational state, where multiple groups of vibration responses within a wide frequency band are used. Hybrid data fusion is applied to process the damage index (DI) constructed based on the multiple responses, leading to detection results capable of indicating delamination positions precisely.

scholarly journals SOUNDNESS EVALUATION OF BRIDGE BEARING BASED ON TWO PLACES DISPLACEMENT MEASUREMENT USING MEMS ACCELEROMETERS

2017 ◽  
Vol 73 (2) ◽  
pp. I_649-I_660
Author(s):  
Hidehiko SEKIYA ◽  
Takeshi KINOMOTO ◽  
Masayuki Tai ◽  
Yusuke Koto ◽  
Osamu Maruyama ◽  
...  
Keyword(s):  
Displacement Measurement ◽  
Mems Accelerometers ◽  
Bridge Bearing

Differential displacement measurement using scanning x-ray beams

1998 ◽  
Vol 69 (2) ◽  
pp. 452-456 ◽  
Author(s):  
Howard A. Canistraro ◽  
Eric H. Jordan ◽  
Douglas M. Pease
Keyword(s):  
Displacement Measurement ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document