USRE46012EActiveUtilityPatentIndex 61

Non-contact probe

Assignee: RENISHAW PLCPriority: Aug 17, 2007Filed: Aug 15, 2008Granted: May 24, 2016

Est. expiryAug 17, 2027(~1.1 yrs left)· nominal 20-yr term from priority

Inventors:WESTON NICHOLAS JOHN HUDDART YVONNE RUTH

G06T 2207/30164G06T 7/0075G01B 11/2527G01B 11/007G01B 11/026G06T 7/0004G06T 7/0057G06T 7/521G06T 7/593

PatentIndex Score

Cited by

235

References

Claims

Abstract

A non-contact measurement apparatus and method. A probe is provided for mounting on a coordinate positioning apparatus, comprising at least one imaging device for capturing an image of an object to be measured. Also provided is an image analyzer configured to analyze at least one first image of an object obtained by the probe from a first perspective and at least one second image of the object obtained by the probe from a second perspective so as to identify at least one target feature on the object to be measured. The image analyzer is further configured to obtain topographical data regarding a surface of the object via analysis of an image, obtained by the probe, of the object on which an optical pattern is projected.

Claims

exact text as granted — not AI-modified

The invention claimed is:

1. A non-contact measurement apparatus, comprising:
a probe configured to be mounted on a coordinate positioning apparatus, comprising an imaging device for capturing an image of an object to be measured;
a processor configured to:
a) analyse at least one first image of an object obtained by the imaging device from a first perspective and at least one second image of the object obtained by the imaging device, which is the same imaging device used to obtain the at least one first image of the object, from a second perspective so as to identify in each of the at least one first image and the at least one second image of the object at least one common photogrammetric target feature on the object to be measured, determine the two-dimensional coordinates of the at least one common photogrammetric target feature on the object within each image, and then, based on knowledge of the relative location and orientation of the imaging device that took the images, determine the three dimensional coordinates of the at least one common photogrammetric target feature; and
b) obtain topographical data regarding a form of a surface of the object via analysis of the distortion of a structured light pattern projected on the object caused by height variation on the surface of the object as imaged in at least one image, obtained by the imaging device, which is the same imaging device used to obtain the at least one first image and the at least one second image of the object,

wherein the non-contact measurement apparatus being further configured to use both the data obtained from a) and b) to provide a 3D point cloud that describes the shape of the object.

2. A non-contact measurement apparatus as claimed in claim 1 , in which the probe comprises at least one projector for projecting an optical pattern onto the surface of the object to be measured.

3. A non-contact measurement apparatus as claimed in claim 1 , in which the processor is configured to obtain the topographical data regarding the surface of the object via analysis of at least one of the at least one first image and the at least one second image.

4. A non-contact measurement apparatus as claimed in claim 1 , in which the processor is configured to process a set of images in which the position of an optical pattern on the object is different for each image in the set in order to determine the topographical data.

5. A non-contact measurement apparatus as claimed in claim 1 , in which the processor is configured to identify an irregularity in an optical pattern projected on the object in each of the first and second images as the at least one common photogrammetric target feature.

6. A non-contact measurement apparatus as claimed in claim 5 , in which the processor is configured to process:
a set of first images obtained by the imaging device from the first perspective, the position of an optical pattern projected onto the object being different for each image in the set; and
a set of second images obtained by the imaging device from the second perspective, the position of an optical pattern projected onto the object being different for each image in the set, in order to identify the at least one common photogrammetric target feature on the object to be measured and to determine the position of the common photogrammetric target feature on the object relative to the an image sensor of the imaging device.

7. A non-contact measurement apparatus as claimed in claim 6 , in which the processor is configured to process at least one of the first or second sets of images in order to determine the topographical data.

8. A non-contact measurement apparatus as claimed in claim 7 , in which the processor is configured to calculate at least one of a first phase map from the set of first images and a second phase map from the set of second images.

9. A non-contact measurement apparatus as claimed in claim 8 , in which the processor is configured to determine the topographical data from at least one of the at least one first phase map and second phase map.

10. A non-contact measurement apparatus as claimed in claim 2 , in which the projector has a fixed optical pattern.

11. A device for use in a non-contact measurement apparatus that includes a probe that is configured to be mounted on a coordinate positioning apparatus, having an imaging device for capturing an image of an object to be measured, the device comprising:
a processor configured to:
a) analyse at least one first image of an object obtained by the imaging device from a first perspective and at least one second image of the object obtained by the imaging device, which is the same imaging device used to obtain the at least one first image of the object, from a second perspective so as to identify in each of the at least one first image and the at least one second image of the object at least one common photogrammetric target feature on the object to be measured, determine the two-dimensional coordinates of the at least one common photogrammetric target feature on the object within each image, and then, based on knowledge of the relative location and orientation of the imaging device that took the images, determine the three dimensional coordinates of the at least one common photogrammetric target feature; and
b) obtain topographical data regarding a form of a surface of the object via analysis of the distortion of a structured light pattern projected on the object caused by height variation on the surface of the object as imaged in at least one image, obtained by the imaging device, which is the same imaging device used to obtain the at least one first image and the at least one second image of the object,

wherein the device being further configured to use both the data obtained from a) and b) to provide a 3D point cloud that describes the shape of the object.

12. A non-contact method for measuring an object located within a measurement space using a probe comprising an imaging device, the method comprising:
a) analysing at least one first image of an object obtained by the imaging device from a first perspective and at least one second image of the object obtained by the imaging device, which is the same imaging device used to obtain the at least one first image of the object, from a second perspective so as to identify in each of the at least one first image and the at least one second image of the object at least one common photogrammetric target feature on the object to be measured, determining the two-dimensional coordinates of the at least one common photogrammetric target feature on the object within each image, and then, based on knowledge of the relative location and orientation of the imaging device that took the images, determining the three dimensional coordinates of the at least one common photogrammetric target feature; and
b) obtaining topographical data regarding a form of a surface of the object via analysis of the distortion of a structured light pattern projected on the object caused by height variation on the surface of the object as imaged in at least one image, obtained by the imaging device, which is the same imaging device used to obtain the at least one first image and the at least one second image of the object,
wherein both the data obtained from a) and b) is used to provide a 3D point cloud that describes the shape of the object.

13. A method as claimed in claim 12 , in which at least one of the at least one first image of the object from the first perspective and at least one second image of the object from the second perspective comprises the at least one image of the object on which an optical pattern is projected.

14. A method as claimed in claim 12 in which the method comprises relatively moving the object and the imaging device between the first and second perspectives.

15. A method as claimed in claim 12 in which the probe comprises a projector for projecting an optical pattern.

16. A memory and a processor, the memory storing instructions which, when executed by the processor, cause the processor to control the probe comprising the imaging device in accordance with the method of claim 12 .

17. A non-transitory computer readable medium storing instructions, which when executed, perform the method of claim 12 .

18. A non-contact measurement apparatus as claimed in claim 1, in which the coordinate positioning apparatus is a coordinate measuring machine.

19. A non-contact measurement apparatus as claimed in claim 1, in which the coordinate positioning apparatus is a machine tool.

20. A non-contact measurement apparatus as claimed in claim 1, in which the probe is mounted on an articulated probe head comprising at least one rotational axis.

21. A non-contact measurement apparatus as claimed in claim 20, in which the articulated probe head comprises at least two rotational axes.

22. A non-contact measurement apparatus as claimed in claim 20, in which the coordinate positioning apparatus comprises a base for the object, a frame on which a quill is mounted which can be moved along three mutually orthogonal axes and on which the articulated probe head is mounted.

23. A method as claimed in claim 12, in which the obtaining topographical data step comprises analysis of at least one of the at least one first image and the at least one second image.

24. A method as claimed in claim 12, in which the method comprises processing a set of images in which the position of an optical pattern on the object is different for each image in the set in order to determine the topographical data.

25. A method as claimed in claim 12, in which the method comprises identifying an irregularity in an optical pattern projected on the object in each of the first and second images as the at least one common photogrammetric target feature.

26. A method as claimed in claim 25, in which the method comprises:
processing a set of first images obtained by the imaging device from the first perspective, the position of an optical pattern projected onto the object being different for each image in the set; and processing a set of second images obtained by the imaging device from the second perspective, the position of an optical pattern projected onto the object being different for each image in the set, in order to identify the at least one common photogrammetric target feature on the object to be measured and to determine the position of the common photogrammetric target feature on the object relative to an image sensor of the imaging device.

27. A method as claimed in claim 26, in which the method comprises processing at least one of the first or second sets of images in order to determine the topographical data.

28. A method as claimed in claim 27, in which the method comprises calculating at least one of a first phase map from the set of first images and a second phase map from the set of second images.

29. A method as claimed in claim 28, in which the method comprises determining the topographical data from at least one of the at least one first phase map and second phase map.

30. A method as claimed in claim 15, in which the projector has a fixed optical pattern.

31. A method as claimed in claim 12, in which the probe is mounted on a coordinate positioning apparatus.

32. A method as claimed in claim 31, in which the coordinate positioning apparatus is a coordinate measuring machine.

33. A method as claimed in claim 31, in which the coordinate positioning apparatus is a machine tool.

34. A method as claimed in claim 31, in which the coordinate positioning apparatus comprises a base for the object, a frame on which a quill is mounted which can be moved along three mutually orthogonal axes and on which an articulated probe head is mounted.

35. A method as claimed in claim 12, in which the probe is mounted on an articulated probe head comprising at least one rotational axis.

36. A method as claimed in claim 35, in which the articulated probe head comprises at least two rotational axes.

Cited by (0)

No later patents cite this yet.

References (0)

No backward citations on record.