A Novel Simple and Low Cost 4-DOF Angular Indexing Calibrating Technique for High Precision Rotary Table

Abstract

For calibrating an angular rotary table, either a high precision standard table or a laser interferometer and related optics are normally employed at high cost. This paper establishes a novel, simple and low cost technique to calibrate a 4-degrees-of-freedom errors of a rotary table (three angular motion errors and one displacement error) for a 360° full circle by employing one reference rotary table, one 1D grating and two 2D (2 dimensional) position-sensing-detectors. With this technique, no highly accurate reference table with good repeatability is needed. After two full circle tests, the 4 DOF errors of the target rotary table and the reference table can be calculated respectively. The angular uncertainty of the measurement system can be less than 1.5 arc sec, while the displacement uncertainty can be up to 1.5 μm.