Precision nano-alignment system using machine vision with motion controlled by piezoelectric motor

In this study, a novel automatic nano-alignment system using machine vision coupled with a piezoelectric motor for motion control was developed. The analytical algorithm of this vision-aided auto-alignment design makes use of inputs of real-time movement captured by CCD to obtain the corresponding output feedback. Through matrix transformation, the algorithm establishes the characteristic matrix of the system. With the feed-in position of the tool, the difference between the fiducial mark and the target position can be obtained by image processing. Alignment commands can then be fed to the two-axis piezoelectric motor to compensate for the positional difference. Both theoretical deductions and experimental trials have proved that the novel automatic vision-aided alignment system is robust and feasible for achieving precision to the nanometer scale.