A new technique based on the reversal method, is suggested to measure squareness error of the two-linear axes system. The technique uses the L-type steel bar, a capacitive sensor, and three experimental installations required to measure squareness error and two horizontal straightness errors. Profile and squareness of the L-type steel bar are estimated, by using the principle of the reversal method. Also, setup errors inevitable at installation, are separated from measured data using the least square method. Multi-DOF errors of two-linear axes system are measured and analyzed, using the suggested technique. Also, the reference mirror with flatness of 30 nm is used to verify the suggested measurement technique. Difference between the two measurement methods is 3.25 arcsec, a value within measurement repeatability.
In this study, the five-DOF motion at ultra-precision linear stage under static and dynamic conditions are evaluated through the extending application of ISO 230-2. As the performance factors, the bi-directional accuracy and repeatability of the five-DOF motion are quantitatively evaluated with the measurement uncertainties which are determined using the standard uncertainty of equipment used in experiment. The motion under static condition are analyzed using geometric errors. The five geometric errors except the linear displacement error are measured using optimal measurement system which is designed to enhance the standard uncertainty of geometric errors. In addition, the motion under dynamic conditions are analyzed with respect to the conditions with different feed rate of the stage. The experimental results shows that the feed rate of stage has a significant effect on straightness motions.