Development of a Coordinate Measuring System with Tracking Laser Interferometers

Summary A highly accurate co-ordinate measuring system for a large measurement area (larger than 1m×1m) is developed. The system consists of two target-tracking stations, each with a laser-interferometer and a twin cube-corner mirror attached to a target. Since the co-ordinate of the target is computed from the radial distances between the target and the rotation axes of the tracking stations, the system can give position-measuring accuracy better than 1μm, regardless of the absolute distances involved. Experimental comparisons between the system developed and a commercial co-ordinate measuring machine show that the position-measuring accuracy of the developed system is better than 1.0 μm in a plane that is 600-800 mm away from the tracking stations.