SIFT-feature-based accuracy measurement method for micro-operation stage

Measuring accuracy of micro-operation stage is quite important due to its significant role played in helping manipulator perform well in location. The paper uses microscopic image to mark the position of micro-operation stage, converts the displacement of stage to the offset of images and then proposes a SIFT-feature-based method of accuracy measurement. Firstly, the paper gives solutions to the key techniques involved in the measurement, including SIFT-feature-based offset measurement of images, calibration of microscopic image and stage's return to reposition measurement point. Then the paper makes exact definition of location accuracy and reposition accuracy according to the motion demand of micro-operation stage and designs the measurement experiment. Furthermore, experiment is accomplished on MR601 stage which verifies the validity of the accuracy measurement method. Meanwhile the result shows that the deviation of 200μm location in Y direction of MR601 stage can be generally within 3μm and the standard deviation of reposition accuracy can be 0.527μm. It can be concluded the reposition accuracy of MR601 stage in Y direction is good.