Share Email Print
cover

Proceedings Paper

Microstructured surface element for high-accuracy position measurement by vision and phase measurement
Author(s): Patrick Sandoz; Bertrand Trolard; D. Marsaut; Tijani Gharbi
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

In interferometry sub-wavelength resolutions are achieved thanks to phase computations. The number of measurement points resolved per fringe depends on the signal to noise ratio and may vary from tens to billions. In this work, that principle of fringe interpolation by phase computation is applied to image processing for the construction of accurate position sensors based on vision. A micro-structured pattern is etched on a surface element and is used as a phase-reference signal similar to an interference fringe pattern. This surface element is fixed on the moving target of interest and is observed by a static vision system. Then target displacements are reconstructed and measured with a high accuracy by locating the phase-reference in the recorded images. In a first configuration in-plane position is retrieved with a resolution of about 10-2 pixel for horizontal and vertical coordinates and about 10-4 radian for the orientation. Thus nanometer displacements can be controlled by a diffractive optical system and micrometer-sized surface patterns. Furthermore, this method is self-calibrating since the phase-reference pattern dimensions are known accurately and then provide us with a size reference available in each recorded image. Different configurations allow the position measurement along the three-space directions while an interferometric set-up is able to locate the position versus the six degrees of freedom. Several measurements per second are performed with an up-to-date microcomputer thanks to the dedicated software developed.

Paper Details

Date Published: 21 October 2004
PDF: 6 pages
Proc. SPIE 5622, 5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications, (21 October 2004); doi: 10.1117/12.591686
Show Author Affiliations
Patrick Sandoz, Institut FEMO-ST, CNRS and Univ. de Franche-Comte (France)
Bertrand Trolard, Institut FEMO-ST, CNRS and Univ. de Franche-Comte (France)
D. Marsaut, Institut FEMO-ST, CNRS and Univ. de Franche-Comte (France)
Tijani Gharbi, Institut FEMO-ST, CNRS and Univ. de Franche-Comte (France)


Published in SPIE Proceedings Vol. 5622:
5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications
Aristides Marcano O.; Jose Luis Paz, Editor(s)

© SPIE. Terms of Use
Back to Top