Laser-based coordinate measuring device and laser-based method for measuring coordinates

• US 7,800,758 B1
• Filed: 07/24/2000
• Issued: 09/21/2010
• Est. Priority Date: 07/23/1999
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Laser Trackers, LLC (Faro Technologies Incorporated)
• Inventors: Ackerson, D. Scott, Brown, Lawrence B., West, James K., Bridges, Robert E.
• Primary Examiner(s): LEE, HWA S
• Application Number:
  US09/621,645
• Time in Patent Office: 3,711 Days
• Field of Search: 356/479, 356/497, 356/3.01, 356/4.09, 356/482, 356/498, 356/500, 356/508
• US Class Current: 356/482
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 11/02 for measuring length, width or thickness G01B11/08 takes precedence
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01B 11/03 by measuring coordinates of points
• CPC Class Codes: G01B 9/02012 using temporal intensity variation
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• 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 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49

Abstract

A laser based coordinate measuring device measures a position of a remote target. The laser based coordinate measuring device includes a stationary portion, a rotatable portion, and at least a first optical fiber. The stationary portion has at least a first laser radiation source and at least a first optical detector, and the rotatable portion is rotatable with respect to the stationary portion. The first optical fiber system, which optically interconnects the first laser radiation source and the first optical detector with an emission end of the first optical fiber system, has the emission end disposed on the rotatable portion. The emission end emits laser radiation to the remote target and receives laser radiation reflected from the remote target with the emission direction of the laser radiation being controlled according to the rotation of the rotatable portion.

Claims

1. A light based coordinate measuring device for measuring a position of a remote target, the measuring device comprising:

a first portion having at least a first light source or a first optical detector;

a second portion rotatable with respect to the first portion;

a first motor structured to rotate the second portion with respect to the first portion;

a first angular encoder to measure the rotation of the second portion about a first axis;

a second motor to rotate the second portion about a second axis;

a second angular encoder to measure the rotation of the second portion about the second axis;

wherein the first and second axes are substantially orthogonal with respect to each other; and

at least a first optical fiber system that connects to both the first light source and the first optical detector, the first optical fiber system having an emission end disposed on the second portion and configured to emit light to the remote target and to receive light reflected from the remote target,

wherein an emission direction of the emitted light to the remote target is fixed with respect to the second portion.

2. The device according to claim 1, wherein the first optical fiber system includes at least first, second, and third optical fibers and a coupler assembly, wherein the third optical fiber has the emission end coupled to the first and second optical fibers by the coupler assembly.

3. The device according to claim 2, wherein the coupler assembly is disposed on one of the second portion and the first portion.

4. The device according to claim 1, wherein the device is structured to determine the distance from the device to the remote target.

5. The device according to claim 1, further comprising a second light source and a second optical fiber system.

6. The device according to claim 5, further comprising a beam combiner disposed on the second portion to combine light emitted from the first and second optical fiber systems into a substantially single composite beam.

7. The device according to claim 6,

wherein the beam combiner includes at least one beam splitter, and

wherein the light from one of the first and second optical fiber systems is transmitted through the beam splitter, and

wherein the light from the other one of the first and second optical fiber systems is reflected off the beam splitter, and

wherein the light transmitted through the beam splitter and the light reflected off the beam splitter are combined.

8. The device according to claim 1, further comprising a beam expander.

9. The device according to claim 1, wherein the remote target includes a retroreflector.

10. The device according to claim 1, further comprising a position detector structured to detect light reflected from the remote target.

11. The device according to claim 1, wherein a segment of the first optical fiber system is disposed near one of the first axis and the second axis.

12. The device according to claim 11, wherein the segment of the first optical fiber system allows rotation about at least one axis without disturbing signals carried by the first optical fiber system.

13. The device according to claim 1, wherein the first optical detector is a part of an absolute distance meter.

14. The device according to claim 13, further comprising an incremental distance meter.

15. The device according to claim 1, wherein the first optical detector is a part of an incremental distance meter.

16. The device according to claim 1, further comprising a locator camera.

17. The device according to claim 1, further comprising an orientation camera structured to image the remote target.

18. The device according to claim 1, wherein the emitted light passes through at least one lens disposed on the second portion.