Improved 3D displacement measurements method and calibration of a combined fringe projection and 2D-DIC system
| Autor: | Philip Siegmann, Luis Felipe-Sesé, Francisco Díaz-Garrido |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Polynomial
Digital image correlation 02 engineering and technology Translation (geometry) 01 natural sciences Displacement (vector) law.invention Structured-light 3D scanner 010309 optics Optics law 0103 physical sciences Calibration Computer vision Electrical and Electronic Engineering Physics Pixel business.industry Mechanical Engineering Astrophysics::Instrumentation and Methods for Astrophysics 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Projector Artificial intelligence 0210 nano-technology business |
| Zdroj: | Optics and Lasers in Engineering. 88:255-264 |
| ISSN: | 0143-8166 |
| DOI: | 10.1016/j.optlaseng.2016.08.014 |
| Popis: | An improved measurement method and an automatic calibration procedure are proposed for a combined 2D Digital Image Correlation and Fringe Projection system that allows measuring in- and out-of-plane displacement maps with only one image at each deformation stage of a specimen. The proposed method increases the accuracy and range of the out-of-plane displacements by taking into account the divergences of both the projected fringes (uncollimated) and the camera (with non-zero FOV). The calibration is performed automatically by acquiring a sequence of images of a reference plane by displacing perpendicular to it the camera and fringe projector with a motorized translation stage. The acquired images are then used to obtain a fringe function for each pixel and the necessary parameters required for the correction of the in-plane displacements. Furthermore, a closed form expression is obtained that relates the out-of-plane displacements with the shifted phase at each pixel for a given experimental set-up. This expression is in good agreement with the fringe function obtained by fitting a simple 2nd order polynomial to the experimental obtained calibration data. Finally, the polynomial approach is proposed as a fringe function because it avoids the errors in the determination of the required parameters of the theoretical expression as well as some small misalignment or aberration effects. |
| Databáze: | OpenAIRE |
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