A Novel Method to Measure Sub-micro Repeatability of the High-Precision Positioning Control System Based on Digital Image Correlation Method

Abstract

To measure and analyze the repeatability of the high-precision positioning control system, an optical technique based on Digital Image Correlation (DIC) method coupling with digital microscope is proposed. In this study, the reliability and feasibility of this method is verified in high-accuracy motorized linear platform, the repeatability of which is calibrated as ±0.3 μm. To determine the in-plane displacement, the DIC requires two speckles images during each hysteresis process to represent the displacement change of platform using digital microscope. In essence, the method can be considered as a “plane to plane” measurement, which can effectively reduce the random error compared to “point to point” measurements. In last, five groups of displacement data under different loadings were obtained and be used to testify the feasibility of this method. In summary, the present study provides a simple, low-cost and efficient non-contact optical technique to detect sub-micro repeatability.