Precision 3-D measurements with a tracking interferometer

Abstract

Measurement of large objects such as aircraft structures and subassemblies of ships has typically been a tedious, labor-intensive process involving manual sighting of targets with theodolites. Simultaneously, there is a strong need for fast, high-precision measurement and control of large coordinate measurement machines (CMMs) and machine tools.A system based on a tracking laser interferometer and a retroreflective target is described which provides a solution for large volume, high speed and high precision measurement and control. The device operates up to a distance of 100 feet and over an angular range of 180° in azimuth and 120° in elevation. Accelerations over 1 g and velocities over 300 inches per minute are being tracked with micron accuracies.Measurement of large objects such as aircraft structures and subassemblies of ships has typically been a tedious, labor-intensive process involving manual sighting of targets with theodolites. Simultaneously, there is a strong need for fast, high-precision measurement and control of large coordinate measurement machines (CMMs) and machine tools.A system based on a tracking laser interferometer and a retroreflective target is described which provides a solution for large volume, high speed and high precision measurement and control. The device operates up to a distance of 100 feet and over an angular range of 180° in azimuth and 120° in elevation. Accelerations over 1 g and velocities over 300 inches per minute are being tracked with micron accuracies.