A low cost measurement method for a large stroke XY nano-positioner by using linear optical encoders

This paper presents a novel measurement method for a large stroke XY nano-positioner (mm-stoke and nanometric accuracy). Based on recently proposed flexure-based large stroke XY nanopositioner, a low cost and simple method is proposed to measure large stroke two-dimensional motion stage. The important feature lies in only two optical gratings are adopted to achieve the measurement for a planner motion, where each optical grating is mounted on a T-shaped flexure beam rather than the ending stage. Moreover the resulting major measurement error is effectively compensated by the designed linear relationship between the stroke and parasitic motion. The experimental results of a 1.0 millimeter circular trajectory tracking is achieved by the proposed method.