Coordinate measurement machines with removable accessories

• US 8,832,954 B2
• Filed: 06/07/2012
• Issued: 09/16/2014
• Est. Priority Date: 01/20/2010
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Faro Technologies Incorporated
• Inventors: Atwell, Paul C., Briggs, Clark H., Stokes, Burnham
• Primary Examiner(s): FULTON, CHRISTOPHER W
• Application Number:
  US13/491,176
• Publication Number:
  US 20130125408A1
• Time in Patent Office: 831 Days
• Field of Search: 335/03
• US Class Current: 33/503
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 11/007 feeler heads therefor
• CPC Class Codes: G01B 11/2509 Color coding
• CPC Class Codes: G01B 11/2513 with several lines being projected in more than one direction, e.g. grids, patterns
• CPC Class Codes: G01B 21/047 Accessories, e.g. for positioning, for tool-setting, for measuring probes
• CPC Class Codes: G01B 2210/58 Wireless transmission of information between a sensor or probe and a control or evaluation unit
• CPC Class Codes: G01B 5/008 using coordinate measuring machines
• CPC Class Codes: G01B 5/012 Contact-making feeler heads therefor
• CPC Class Codes: G05B 19/401 characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/33162 Two bus, high speed and low speed bus, linked or not
• 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 portable articulated arm coordinate measuring machine is provided. The coordinate measuring machine includes a base with an arm portion. A probe end is coupled to an end of the arm portion distal from the base. A device configured to emit a coded structured light onto an object to determine the three dimensional coordinates of a point on the object.

Claims

1. A portable articulated arm coordinate measuring machine (AACMM) for measuring three-dimensional coordinates of an object in space, comprising:

a base;

a manually positionable arm portion having an opposed first end and second end, the arm portion being rotationally coupled to the base, the arm portion including a plurality of connected arm segments, each arm segment including at least one position transducer for producing a position signal;

an electronic circuit which receives the position signal from the at least one position transducer in each arm segment;

a probe end coupled to the first end;

a noncontact three-dimensional measuring device coupled to the probe end, the noncontact three-dimensional measuring device having a projector and an image sensor, the projector having a source plane, the projector configured to emit a structured light onto the object, the structured light emitted from the source plane and including at least three non-collinear pattern elements, the image sensor arranged to receive the structured light reflected from the object; and

a processor electrically coupled to the electronic circuit, the processor configured to determine the three-dimensional coordinates of a point on the object in response to receiving the position signals from the position transducers and in response to receiving the structured light by the image sensor.

2. The AACMM of claim 1 wherein the noncontact three-dimensional measuring device is removably coupled to the probe end.

3. The AACMM of claim 1 wherein the structured light is a coded structured light pattern.

4. The AACMM of claim 3 wherein the noncontact three-dimensional measuring device is independently operable when detached from the probe end.

5. The AACMM of claim 3 wherein the coded structured light pattern comprises graphical elements that include at least one of a square, rectangle and triangle.

6. The AACMM of claim 5 wherein the coded light pattern is a sinusoidal pattern that includes 30 lines and each line is 180 degrees out of phase with respect to adjacent lines.

7. The AACMM of claim 5 wherein the coded structured light pattern includes 27 lines and the graphical elements are squares.

8. The AACMM of claim 3 wherein the coded structured light includes a pattern having a plurality of wavelengths, wherein at least one wavelength has a different spatial arrangement than the other wavelengths.

9. The AACMM of claim 3 wherein the coded structured light includes a pattern having a plurality of distinct colors.

10. The AACMM of claim 3 wherein the coded structured light includes a segmented line pattern.

11. The AACMM of claim 3 wherein the coded structured light includes a two-dimensional spatial grid pattern.

12. The AACMM of claim 11 wherein the two-dimensional spatial grid pattern includes a pseudo-random binary array.

13. The AACMM of claim 11 wherein the two-dimensional spatial grid pattern includes a color coded grid.

14. The AACMM of claim 11 wherein the two-dimensional spatial grid pattern includes a multi-valued pseudo random array.

15. The AACMM of claim 11 wherein the two-dimensional spatial grid pattern includes a two-dimensional array of color-coded geometric shapes.

16. The AACMM of claim 1 wherein the structured light pattern is an uncoded structured light pattern.

17. The AACMM of claim 16 wherein the uncoded structured light pattern includes sequential projection images.

18. The AACMM of claim 17 wherein the sequential projection images are a set of binary patterns.

19. The AACMM of claim 17 wherein the sequential projection images are a set of patterns including stripes having at least two levels of intensity.

20. The AACMM of claim 17 wherein the sequential projection images are a set of at least three sinusoidal patterns.

21. The AACMM of claim 17 wherein the sequential projection images are a set of patterns including stripes having at least two levels of intensity which include at least three sinusoidal patterns.

22. The AACMM of claim 16 wherein the uncoded structured light pattern projects a sequence of different illuminated patterns, each of the sequence of different illuminated patterns being projected from different locations relative to the object.

23. The AACMM of claim 16 wherein the uncoded structured light pattern includes a repeated grey scale pattern.

24. The AACMM of claim 1 further comprising a contact measurement device coupled to the probe end.

25. The AACMM of claim 1 wherein the processor is located within the noncontact three-dimensional measuring device.

26. A method of operating a portable articulated arm coordinate measuring machine for measuring the coordinates of an object in space, comprising:

providing a manually positionable arm portion having an opposed first end and second end, the arm portion including a plurality of connected arm segments, each arm segment including at least one position transducer for producing a position signal;

providing a probe end for measuring the object, the probe end being coupled to the first end;

receiving at an electronic circuit the position signals from the transducers;

providing a three-dimensional noncontact measurement device having a controller, the three-dimensional noncontact measurement device having a sensor and a projector, the projector configured to emit a structured light onto the object, the projector having a source plane, the structured light emitted from the source plane and including at least three non-collinear pattern elements; and

projecting a structured light from the three-dimensional measurement device onto the object.

27. The method of claim 26 further comprising receiving a reflection of the structured light from the object with the three-dimensional measurement device.

28. The method of claim 27 further comprising determining three-dimensional coordinates of a point on the object from the reflected structured light.

29. The method of claim 28 wherein the structured light is a coded structured light.

30. The method of claim 29 wherein the coded structured light pattern projected onto the object comprises graphical elements that include at least one of a square, rectangle and triangle.

31. The method of claim 29 wherein the coded light pattern is a sinusoidal pattern that includes 30 lines and each line is 180 degrees out of phase with respect to adjacent lines.

32. The method of claim 29 wherein the coded structured light pattern includes 27 lines and the graphical elements are squares.

33. The method of claim 29 wherein the coded structured light includes a pattern having a plurality of wavelengths, wherein at least one wavelength has a different spatial arrangement than the other wavelengths.

34. The method of claim 33 wherein the pattern having a plurality of wavelengths is arranged into lines oriented substantially perpendicular to the source plane.

35. The method of claim 29 wherein the coded structured light includes a single pattern having a plurality of distinct colors.

36. The method of claim 29 wherein the coded structured light includes a segmented line pattern.

37. The method of claim 29 wherein the coded structured light includes a two-dimensional spatial grid pattern.

38. The method of claim 37 wherein the two-dimensional spatial grid pattern includes a pseudo-random binary array.

39. The method of claim 37 wherein the two-dimensional spatial grid pattern includes a color coded grid.

40. The method of claim 37 wherein the two-dimensional spatial grid pattern includes a multi-valued pseudo random array.

41. The method of claim 37 wherein the two-dimensional spatial grid pattern includes a two-dimensional array of color-coded geometric shapes.

42. The method of claim 29 further comprising changing the coded structured light from a first pattern to a second pattern with the electronic circuit.

43. The method of claim 42 wherein the coded structured light is changed in response to an operator input.

44. The method of claim 42 wherein the coded structured light is changed automatically by the electronic circuit in response to a change in conditions on the object.

45. The AACMM of claim 28 further comprising:

separating the three-dimensional measurement device from the probe end; and

operating the three-dimensional measurement device separately from the probe end.

46. The AACMM of claim 45 further comprising transmitting data from the three-dimensional measurement device operating separately from the probe end.