ARTICULATING MEASURING ARM WITH LASER SCANNER

• US 20100095542A1
• Filed: 06/18/2009
• Published: 04/22/2010
• Est. Priority Date: 10/16/2008
• Status: Active Grant

• Current Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Original Assignee: Romer Incorporated (Hexagon AB)
• Inventors: Ferrari, Paul
• Granted Patent: US 7,908,757 B2
• Time in Patent Office: Days
• US Class Current: 33/503
• CPC Class Codes: G01B 11/007 feeler heads therefor
• CPC Class Codes: G01B 11/022 by means of tv-camera scanning
• CPC Class Codes: G01B 5/012 Contact-making feeler heads therefor
• CPC Class Codes: Y10S 33/21 with laser

Abstract

A coordinate measurement device comprises an articulated arm having a first end, a second end, and a plurality of jointed arm segments therebetween. Each arm segment defines at least one axis of rotation. A laser scanner assembly is coupled to the second end of the arm and is rotatable about a last axis of rotation of the articulated arm. The laser scanner assembly comprises a laser and an image sensor. The laser is positioned on an opposite side of the last axis of rotation from the image sensor.

Claims

1. An optical position acquisition member comprising:

a base plate comprising an opening configured to receive a CMM measuring probe;

a laser mounted on the plate; and

an optical sensor mounted on the plate such that the sensor is generally collinear with the laser and the opening, and the opening is between the laser and the sensor.

2. The acquisition member of claim 1, wherein the base plate comprises a material selected from the group consisting of invar, ceramic, steel, aluminum, plastic, or a carbon composite.

3. The acquisition member of claim 1, wherein the laser is within 100 mm of a center of the opening.

4. The acquisition member of claim 1, further comprising a first housing mounted on the base plate and substantially enclosing the optical sensor.

5. The acquisition member of claim 1, wherein two or more optical sensors are mounted to the base plate.

6. The acquisition member of claim 4, further comprising electronics in the first housing, operatively connected to the optical sensor.

7. The acquisition member of claim 5, wherein the electronics are thermally isolated from the laser.

8. The acquisition member of claim 1, wherein the base plate is configured to rotatably mount to the probe, such that the base plate can rotate independent of the probe.

9. An articulated arm CMM comprising:

an articulated arm comprising a plurality of articulated arm members, a measuring probe, a receiving portion at a distal end, and a base at a proximal end; and

a base plate mounted on the receiving portion, the plate comprising a hole positioned such that the measuring probe passes through the hole, the base plate coupled to a laser and an optical sensor located on opposite sides of the hole.

10. The CMM of claim 9, wherein the articulated arm further comprises a last axis of rotation, the laser being oriented generally parallel to the last axis of rotation and within 100 mm of the last axis of rotation.

11. The CMM of claim 9, wherein the articulated arm further comprises a second to last axis of rotation and the optical sensor further comprises a focus, the focus being within 100 mm of the second to last axis of rotation.

12. The CMM of claim 9, wherein two or more optical sensors are mounted to the baseplate.

13. The CMM of claim 9, wherein the receiving portion comprises bearings and at least a portion of the laser or the optical sensor overlaps the bearings.

14. The CMM of claim 9, wherein the base plate is rotatably mounted on the receiving portion such that it is rotatable independent of the probe.

15. A coordinate measurement device comprising:

an articulated arm having a first end, a second end, and a plurality of jointed arm segments therebetween, each arm segment defining at least one axis of rotation, a last axis of rotation being defined by bearings near a distal end of the arm; and

a laser scanner assembly coupled to the second end of the arm and rotatable about the last axis of rotation of the articulated arm, the laser scanner assembly comprising a laser and an image sensor, the laser positioned on an opposite side of the last axis of rotation from the image sensor, and at least one of the laser and image sensor overlaps the bearings.

16. The coordinate measurement device of claim 15, further comprising a probe positioned between the laser and image sensor.

17. The coordinate measurement device of claim 16, wherein the probe is a touch probe.

18. The coordinate measurement device of claim 16, wherein the probe is positioned substantially along the last axis of rotation.

19. The coordinate measurement device of claim 15, where the laser and image sensor are mounted to a common plate.

20. The coordinate measurement device of claim 19, wherein the common plate is made of Invar.

21. The coordinate measurement device of claim 19, wherein the common plate includes an opening through which the last axis of rotation extends.

22. The coordinate measurement device of claim 21, wherein a probe extends through the opening in the common plate.

23. The coordinate measurement device of claim 22, wherein the probe is a touch probe.

24. The coordinate measurement device of claim 16, wherein the laser scanner assembly is rotatable relative to the probe.