Concurrent measurement of radial, axial and angular motions of spindle using concentric circle grating interferometers(3rd report: Measurements of 5 degree freedom error motions)

摘要

In this paper, we describe a concurrent measurement of radial, axial and angular motions of spindle using concentric circle grating interferometers. The concentric circle grating is used as reference artifact which is installed on the top of the spindle. Three optical sensors, consist of a laser as a light source and two interferometers, are fixed over the grating. The interferometer observes an interference signal between reflection lights from a fixed mirror and the 0th-order diffraction light from the grating for vertical displacement measurement. The other interferometer observes an interference signal between ±1st-order diffraction lights from the grating for lateral displacement measurement. Using three optical sensors placed at appropriate position of the grating, the vertical and lateral displacement of grating can be measured, and then the radial, axial and angular error motions of spindle can be determined.