Twin-scale Vernier Micro-pattern for Visual Measurement of 1-D in-plane Absolute Displacements with Increased Range-to-Resolution Ratio.
Fiche publication
Date publication
juillet 2013
Auteurs
Membres identifiés du Cancéropôle Est :
Dr SANDOZ Patrick
Tous les auteurs :
Zea JG, Sandoz P, Laurent GJ, Lemos LL, Clevy C
Lien Pubmed
Résumé
This article presents a visual method for 1-D in-plane displacement measurement which combines a resolution of a few nanometers with an unambiguous excursion range of 168 mu m. Furthermore, position retrieval is only based on elementary phase computations and, thus, might become compatible with high-rate processing by implementing the processing algorithm on high speed computing architectures, like a DSP or a FPGA device. The method is based on a twin scale Vernier micro-pattern fixed on the moving target of interest. The two periodic grids have slightly different periods in order to encode the period order within the phase difference observed between the two sub-patterns. As a result, an unambiguous range of 168 mu m is obtained from grid periods of 8 mu m and 8.4 mu m. The resolution is evaluated to be of 11.7nm despite remaining mechanical disturbances. Differential measurements demonstrated indeed a measurement accuracy better than 5nm.
Référence
Int J Optomechatronics. 2013 Jul 3;7(3):222-34.