3D interferometric measurement system for machine tool on-line control

We present the definition and development of a three dimensional high precision measurement system for localisation and control of machine tool's drill based on a Michelson-Morley interferometric configuration and a laser tracking subsystem to redirect the measurement beam onto a retro-reflector positioned in the tool nearness. The system measures the retro-reflector position in real time with 5 microns accuracy up to 2 m/s processing material velocities and it is used to carry out an on-line control feedback of the drill position in the machine tool allowing a drill tool replacement during the fabrication process. The system has been integrated and tested in an especially designed machine tool built for this application.