Apparatus and method for relocating an articulating-arm coordinate measuring machine

• US 7,804,602 B2
• Filed: 06/23/2006
• Issued: 09/28/2010
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Raab, Simon
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US11/473,710
• Publication Number:
  US 20090177438A1
• Time in Patent Office: 1,558 Days
• Field of Search: 356614-622, 356/2, 356601-613
• US Class Current: 356/614
• CPC Class Codes: G01B 21/04 by measuring coordinates of points
• CPC Class Codes: G01D 18/004 Continuous recalibration
• CPC Class Codes: G01D 5/305 controlling the movement of a following part
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G05B 2219/33263 Conversion, transformation of coordinates, cartesian or polar
• CPC Class Codes: G05B 2219/37193 Multicoordinate measuring system, machine, cmm
• CPC Class Codes: G05B 2219/40233 Portable robot
• CPC Class Codes: G05B 2219/45061 Measuring robot

Abstract

A measurement apparatus, system and method for measuring objects which is easily relocatable about the object is described. The system uses an articulated-arm coordinate measuring machine (CMM) and a laser tracker. A retroreflector for use with the laser tracker is located on the arm of the articulated-arm (CMM). A common coordinate frame of reference can be determined for the CMM and the laser tracker so that the CMM can be moved. Also, points hidden from the laser tracker can be measured for example with the CMM.

Claims

1. A system for coordinate measurement comprising:

a laser tracker;

a relocatable articulated-arm coordinate measuring machine; and

a retroreflector located on the articulated-arm coordinate measuring machine;

wherein the laser tracker sends a laser beam to the retroreflector to measure at least three positions of the retroreflector relative to the laser tracker in a first coordinate system while the articulated-arm coordinate measuring machine measures the at least three positions of the retroreflector relative to the articulated-arm coordinate measuring machine in a second coordinate system; and

wherein the articulated-arm coordinate measuring machine is relocated to a different position and the laser tracker sends the laser beam to the retroreflector to measure at least three positions of the retroreflector relative to the laser tracker in the first coordinate system while the articulated-arm coordinate measuring machine measures the at least three positions of the retroreflector relative to the articulated-arm coordinate measuring machine in the second coordinate system; and

means for transforming the first coordinate system and/or the second coordinate system to a common coordinate frame of reference.

2. The system of claim 1 wherein the laser tracker is fixed in place.

3. The system of claim 1 wherein the retroreflector comprises a spherically mounted retroreflector.

4. The system of claim 1 wherein the retroreflector comprises a cube-corner retroreflector.

5. A laser measurement apparatus for measuring objects comprising:

an articulated-arm coordinate measuring machine;

a laser tracker; and

a retroreflector located on an arm of the articulated-arm coordinate measuring machine;

wherein the laser tracker sends a laser beam to the retroreflector to measure at least three positions of the retroreflector relative to the laser tracker in a first coordinate system while the articulated-arm coordinate measuring machine measures the at least three positions of the retroreflector relative to the articulated-arm coordinate measuring machine in a second coordinate system; and

wherein the articulated-arm coordinate measuring machine is relocated to a different position and the laser tracker sends a laser beam to the retroreflector to measure at least three positions of the retroreflector relative to the laser tracker in the first coordinate system while the articulated-arm coordinate measuring machine measures the at least three positions of the retroreflector relative to the articulated-arm coordinate measuring machine in the second coordinate system.