A macro-micro compensation method for straightness motion error and positioning error of an improved linear stage

This research developed a linear stage with improved structures for reducing the error sources and proposed a macro-micro compensation method for both the straightness motion error and positioning error. One improved structure saw flexible steel sheet joints used instead of a rigid plate between the slide and nut to reduce radial error caused by the ball screw nut; the other saw a fine adjustment mechanism used for adjusting the installation angle of the adjustable guideway to reduce parallelism error. A high-precision two-axis (X and Y) micro-stage driven by piezoelectric (PZT) actuator was installed on the improved linear stage (macro-stage), and then compensations for straightness motion error and positioning error were achieved by utilizing the compensation motions of the XY-micro-stage after the coarse motion of the macro-stage. Experiments on the improved linear stage were conducted to verify the effectiveness of the proposed methods. The results have shown that the straightness motion error of the slide was compensated from 1.61 mu m/100 mm to 0.55 mu m/100 mm, and the forward mean and reverse mean of the positioning error were respectively compensated from 3.05 mu m/100 mm and 3.23 mu m/100 mm to 0.69 mu m/100 mm and 0.79 mu m/100 mm.