In-plane micro-motion measurement with high accuracy based on computer microvision

Micro-motion measurement with high accuracy plays a vital role in micro/nano manufacturing technology. In this paper, an integrated approach for measuring micro-motion that incorporates motion estimation algorithm into the computer microvision is proposed. At first, the basic principle of the computer microvision measurement is analyzed. Then, a robust multiscale motion estimation algorithm for micro-motion measurement is proposed. In this algorithm, according to the different properties of filters, motion at each level of the pyramid is estimated using different gradient filters. This hierarchical estimation technique not only provides an improvement in measurement accuracy, but also achieves measurement speedups. Finally, using the micropositioning stage as measurement objects, the micro-motions are measured using the integrated approach that incorporates this algorithm into computer microvision. The maximal bias of this integrated approach reached 12.5 nm for motions near 2000 nm. Experimental results show that the new integrated method can measure in-plane micro-motions with high accuracy.