Articulating measuring arm with optical scanner

• US 8,955,229 B2
• Filed: 04/17/2013
• Issued: 02/17/2015
• Est. Priority Date: 10/16/2008
• Status: Active Grant

• Current Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Original Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Inventors: Ferrari, Paul
• Primary Examiner(s): Bennett, G. Bradley
• Application Number:
  US13/864,961
• Publication Number:
  US 20140098378A1
• Time in Patent Office: 671 Days
• Field of Search: 335/03, 33D/IG.21, 356/614
• 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 light source mounted on the place; and

an optical sensor mounted on the plate such that the sensor is generally collinear with the light source and the opening, and the opening is between the light source 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 light source 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 6, wherein the electronics are thermally isolated from the light source.

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 light source 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 light source 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 light source 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

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

16. The coordinate measurement device of claim 15, further comprising a probe positioned between the light source 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 light source 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 22, wherein the optical scanner assembly is rotatable relative to the probe.

25. The coordinate measurement device of claim 15, wherein the optical scanner assembly comprises two or more image sensors.

26. An optical position acquisition member comprising:

a base member forming an opening shaped to accept a CMM measuring probe such as a touch probe;

a light source mounted on the base member; and

an optical sensor associated with the light source such that the optical sensor operatively views light emitted by the light source and reflected from a surface, the optical sensor further being mounted to the base member on a side of the opening opposite the light source.

27. The acquisition member of claim 26, wherein the base member comprises a material selected from the group consisting of invar, ceramic, steel, aluminum, plastic, or a carbon composite.

28. The acquisition member of claim 26, wherein the light source is within 100 mm of a center of the opening.

29. The acquisition member of claim 26, further comprising a first housing mounted on the base member and substantially enclosing the optical sensor.

30. The acquisition member of claim 26, wherein two or more optical sensors are mounted to the base member.

31. The acquisition member of claim 29, further comprising electronics in the first housing, operatively connected to the optical sensor.

32. The acquisition member of claim 31, wherein the electronics are thermally isolated from the light source.

33. The acquisition member of claim 26, wherein the base member is configured to rotatably mount to the probe, such that the base member can rotate independent of the probe.

34. An optical position acquisition member comprising:

a main body configured to mount to a coordinate measuring machine, the main body comprising a first housing and a second housing separate from the first housing;

a light source and an optical sensor configured to receive light from said light source to form an optical scanner, at least the optical sensor being disposed in the first housing; and

electronics associated with said optical scanner disposed in the second housing separate from the first housing.

35. The optical position acquisition member of claim 34, wherein the optical sensor is thermally isolated from the electronics associated with the light source and optical sensor.

36. The optical position acquisition member of claim 34, wherein the main body comprises a base plate connected to each of the first and second housing.

37. The optical position acquisition member of claim 36, wherein the base plate comprises an opening configured to receive a coordinate measuring machine measuring probe.

38. The optical position acquisition member of claim 34, wherein the light source is mounted to the main body separate from the first and second housings.

39. The optical position acquisition member of claim 34, wherein the first housing substantially encloses the optical sensor.

40. The optical position acquisition member of claim 34, wherein the main body comprises a material selected from the group consisting of invar, ceramic, or carbon fiber.

41. The optical position acquisition member of claim 34, comprising two or more optical sensors configured to receive light from said light source.

42. An articulated arm coordinate measuring machine comprising:

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

an optical scanner mounted to the receiving portion at a distal end of the articulated arm and comprising a light source, an optical sensor, and electronics associated with the light source and the optical sensor, at least the optical sensor being disposed in a first housing and at least a portion of the electronics being disposed in the second housing.

43. The articulated arm coordinate measuring machine of claim 42, wherein the optical sensor is thermally isolated from the electronics associated with the optical scanner.

44. The articulated arm coordinate measuring machine of claim 42, wherein the first housing is disposed on one of the articulated arm members.

45. The articulated arm coordinate measuring machine of claim 42, wherein the second housing is disposed on one of the articulated arm members.

46. The articulated arm coordinate measuring machine of claim 42, wherein all the electronics are disposed in the second housing.

47. The articulated arm coordinate measuring machine of claim 42, wherein the optical scanner comprises a base plate connected to each of the first and second housing.

48. The articulated arm coordinate measuring machine of claim 47, wherein the base plate comprises an opening configured to receive a coordinate measuring machine measuring probe.

49. The articulated arm coordinate measuring machine of claim 42, wherein the optical scanner is mounted separate from the first and second housings.

50. The articulated arm coordinate measuring machine of claim 42, wherein the first housing substantially encloses the optical sensor.

51. The articulated arm coordinate measuring machine of claim 42, wherein the optical scanner comprises a material selected from the group consisting of invar, ceramic, or carbon fiber.

52. The articulated arm coordinate measuring machine of claim 42, wherein the optical scanner comprising two or more optical sensors.