Microstructured surface element for high-accuracy position measurement by vision and phase measurement

Patrick Sandoz; Bertrand Trolard; D. Marsaut; Tijani Gharbi

doi:10.1117/12.591686

21 October 2004 Microstructured surface element for high-accuracy position measurement by vision and phase measurement

Patrick Sandoz, Bertrand Trolard, D. Marsaut, Tijani Gharbi

Proceedings Volume 5622, 5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications; (2004) https://doi.org/10.1117/12.591686
Event: 5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications, 2004, Porlamar, Venezuela

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.

Citation Download Citation

Patrick Sandoz, Bertrand Trolard, D. Marsaut, and Tijani Gharbi "Microstructured surface element for high-accuracy position measurement by vision and phase measurement", Proc. SPIE 5622, 5th Iberoamerican Meeting on Optics and 8th Latin American Meeting on Optics, Lasers, and Their Applications, (21 October 2004); https://doi.org/10.1117/12.591686

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available