Self-compensating laser tracker

Abstract

An apparatus and method for compensating a coordinate measurement machine is provided, which may be, e.g. a laser-based coordinate measurement machine, laser tracker, or other coordinate measurement device. In one exemplary method, such compensation comprises self-compensation of payload parameters by means of embedded tracker targets. In another exemplary embodiment, such compensation comprises self compensation of payload, azimuth-post, axis, or RO parameters by means of embedded temperature sensors.

Description

technical background [0001] The present disclosure relates to coordinate measuring equipment. A coordinate measuring device is a class of instruments that measure the coordinates of a point by firing a laser beam at the point. The laser beam may be directed onto the point or may be directed onto a retroreflector target in contact with the point. In either case, the instrument determines the coordinates of the point by measuring the distance to the target and two angles. Distances are measured with distance measuring devices such as absolute range finders or interferometers. The angle is measured with an angle measuring device, such as an angle encoder. A gimbaled beam steering mechanism inside the instrument directs the laser beam to the point of interest. Example systems for determining coordinates of points are described in Brown et al., US Patent 4,790,651 and Lau et al., US Patent 4,714,339. [0002] A laser tracker is a special class of coordinate measuring device th...

AI Technical Summary

Problems solved by technology

These will take anywhere from a few minutes to one or more hours, depending on the specific tracker and required tests

In most cases, while mechanical vibration is also a significant cause of loss of tracker accuracy, the main cause is thermal drift, so new methods of compensating for CMMs are needed

Images