Self-compensating laser tracker

• US 7,327,446 B2
• Filed: 09/07/2004
• Issued: 02/05/2008
• Est. Priority Date: 09/05/2003
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: West, James K., Bridges, Robert E., Cramer, Peter G.
• Primary Examiner(s): Punnoose; Roy M.
• Application Number:
  US10/935,459
• Publication Number:
  US 20050179890A1
• Time in Patent Office: 1,246 Days
• Field of Search: 356/154
• US Class Current: 356/154
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G02B 5/122 cube corner, trihedral or triple reflector type

Abstract

An apparatus and method for compensating a coordinate measurement machine is provided, which may be 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 R0 parameters by means of embedded temperature sensors.

Claims

1. A self-compensating laser tracker that emits a laser beam, comprising:

a rotatable payload from which the laser beam is emitted;

at least two embedded, non-moveable, reflecting members provided on a support for the payload;

wherein one of said at least two reflecting members is a cube corner retroreflector and a second of said at least two reflecting members is a mirror and

wherein the cube corner retroreflector and the mirror are fixed in position on the support relative to the rotablable payload and relative to each other and are structured to reflect the laser beam in a frontsight mode and a backsight mode when the payload is rotated accordingly in order to determine and then self-compensate for deviations in desired payload parameters where the payload parameters describe position and orientation of the laser beam.

2. A self-compensating laser tracker in accordance with claim 1, wherein said support comprises a gimbaled mechanism.

3. A self-compensating laser tracker in accordance with claim 2, wherein said gimbaled mechanism produces motion in the azimuth and zenith directions.