Metrology system for the calibration of multi-dof precision mechanisms

摘要

We have developed a novel metrology system for precision XY measurements based on a concept developed originallyin an industrial vision context by which USB cameras observe a target with a special dots pattern. The system has thenbeen extended to Rx-Ry (tip-tilt), Z and Rz measurements by adding more cameras within a suitable configuration. Thebasic principle is described, first validated on a preliminary experimental implementation used for testing a new type ofhexapod. We then illustrate the setup designed as calibration bench for hexapods used as positioning devices of thesecondary mirrors of astronomical telescopes. While work is still ongoing for improving this new metrology system,currently achieved performances are a stability of is ≤1 μm along linear degrees of freedom, respectively 0.5 arcsec fortip-ti absolute accuracy over ranges of a few millimeters is 5-10 μm , respectively arcsec; incremental accuracy is 2-3μm, respectively 5 arcsec.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.