CONCURRENT MEASUREMENT OF SPINDLE RADIAL, AXIAL AND ANGULAR MOTIONS USING CONCENTRIC CIRCLE GRATING AND PHASE MODULATION INTERFEROMETERS

摘要

This paper describes a concurrent measurement of spindle radial, axial and angular motions using concentric circle grating and phase modulation interferometers. In the measurement, the concentric circle grating with fine pitch is a reference artifact. A frequency modulated laser diode is used for the light source of the phase modulation interferometers. The phase modulation interferometers, which consist of three Michelson and three grating interferometers, measure three radial and three axial displacements of the grating. From these six measured displacements, radial, axial and angular motions of the spindle can be determined concurrently. In the paper, a measurement principle, a measurement instrument and experimental results are discussed. Concurrent measurements of spindle radial, axial and angular motions were successfully attained.