Positional error compensation of a precision microstage

摘要

In this paper, an experimental calibration, using a laser interferometer, was carried out on the positioning accuracy of a precision microstage. With larger incremental steps, the two harmonics of the cyclic error, caused by the driving mechanism, could be clearly seen with a magnitude up to several microns. With smaller incremental steps, the third cyclic error, caused by the motor mechanism was revealed with a magnitude up to 0.6μm. Mathematical models of the examined cyclic errors were derived respectively, and stored in the error budget. A feed-forward error compensation strategy was employed during the position control of the microstage. Having removed the cyclic errors, the positioning accuracy of the stage could be enhanced from ±2.5μm to ±0.5μm for coarse steps, and from 0.6μm to ±0.1μm for fine steps. A great improvement was achieved.