Articulated arm coordinate measuring machine having a color laser line probe

Patent metadata

Field	Value
Publication number	US-2019063899-A1
Application number	US-201815894060-A
Country	US
Kind code	A1
Filing date	Feb 12, 2018
Priority date	Aug 29, 2017
Publication date	Feb 28, 2019
Grant date	—

Abstract

An articulated arm coordinate measuring machine includes a laser line probe. The laser line probe includes a camera that can acquire metrology data and color data. A laser line probe is coupled to a probe end of an articulated arm. The laser line probe having a projector and a camera, the projector being operable to project a line of light at one or more predetermined wavelengths, the camera having a lens assembly optically coupled to a sensor assembly. The sensor assembly has a photosensitive array and a filter disposed between the photosensitive array and the lens assembly. The filter includes a plurality of red, green and blue pixels in a predetermined arrangement. A controller is coupled to the laser line probe and causes the camera to acquire a metrology image and a color image. The controller assigns a color to the three-dimensional coordinate points based on the color image.

First claim

1 . A portable articulated arm coordinate measuring machine (AACMM) for measuring the coordinates of an object in space, comprising:
a base; a manually positionable arm portion coupled to the base and having an end opposite the base; a measurement device coupled to the end; an electronic circuit that is operable to determine a position of the measurement device relative to a frame of reference; a laser line probe operably coupled to the end, the laser line probe having a projector and a camera, the projector being operable to project a line of light at one or more predetermined wavelengths, the camera having a lens assembly optically coupled to a sensor assembly, the sensor assembly having a photosensitive array and a filter disposed between the photosensitive array and the lens assembly, the filter having a plurality of red, green and blue pixels in a predetermined arrangement; and a controller operably coupled to the laser line probe, the controller being operable to cause the camera to acquire a metrology image and a color image, wherein the controller and the electronic circuit cooperate to determine the three-dimensional coordinates of points on a surface based at least in part on the metrology image and to assign a color to the points based at least in part on the color image.

2 . The AACMM of claim 1 , wherein the controller is operable to acquire the metrology image and the color image in an interleaved sequence.

3 . The AACMM of claim 2 , wherein the interleaving ratio of metrology images to color images is greater than 1:1.

4 . The AACMM of claim 2 , wherein the controller is operable to cause the metrology image to be acquired when the projector emits the line of light.

5 . The AACMM of claim 2 , further comprising a light source operably coupled to the controller, wherein the controller is further operable to activate the light source when the color image is acquired.

6 . The AACMM of claim 5 , wherein the light source is an RGB laser.

7 . The AACMM of claim 1 , wherein the one or more predetermined wavelengths are between 450-495 nm.

8 . The AACMM of claim 7 , wherein the one or more predetermined wavelengths is 450 nm.

9 . The AACMM of claim 1 , wherein the one or more predetermined wavelengths is 532 nm.

10 . The AACMM of claim 1 , wherein the one or more predetermined wavelengths is between 500-520 nm.

11 . The AACMM of claim 1 , wherein:
the photosensitive array includes a plurality of photosensitive array pixels, each of the plurality of photosensitive array pixels being aligned with one of the filter elements; the controller is further operable to receive pixel values from a first portion of the plurality of photosensitive array pixels and interpolate pixel values to a second portion of the plurality of photosensitive array pixels; and the controller is further operable to determine center of gravity locations based at least in part on the pixel values of the first portion and the second portion of the plurality of photosensitive array pixels.

12 . The AACMM of claim 11 , wherein the controller is further operable to determine colors of a predetermined number of pixels adjacent to each center of gravity location, and wherein the assignment of color is based at least in part on the determined colors.

13 . The AACMM of claim 1 , wherein the filter is a Bayer filter.

14 . The AACMM of claim 1 , wherein the laser line probe further comprises at least one light source that during operation selectively emit a white light onto the surface.

15 . A method of determining three-dimensional coordinates of points on a surface, the method comprising:
emitting a line of light from a projector in a laser line probe coupled to the end of an articulated arm onto a surface of an object; acquiring with a first portion of pixels on a photosensitive array in a camera in the laser line probe a metrology image of the line of light on the surface, the camera having a filter, the filter having a predetermined arrangement of red, green and blue pixels; determining a plurality of center of gravity locations based at least in part on the metrology image; acquiring with the photosensitive array a color image; and assigning a color to each of the center of gravity locations based at least in part on the color image.

16 . The method of claim 15 , wherein the metrology image is acquired in a first instance and the color image in a second instance.

17 . The method of claim 16 , wherein a plurality of metrology images are acquired between each color image.

18 . The method of claim 15 , wherein the line of light is emitted when the metrology image is acquired.

19 . The method of claim 15 , wherein the photosensitive array includes the first portion of pixels, a second portion of pixels and a third portion of pixels.

20 . The method of claim 19 , further comprising:
receiving first pixel values from the first portion of pixels; estimating second pixel values for the second portion of pixels from the first pixel values; estimating third pixel values for the third portion of pixels from the first pixel values; and wherein the plurality of center of gravity locations are based at least in part on the first pixel values, the second pixel values, and the third pixel values.

21 . The method of claim 20 , wherein the first portion of pixels are aligned with the blue filter pixels, the second portion of pixels are aligned with the red filter pixels, and the third portion of pixels are aligned with the green filter pixels.

22 . The method of claim 20 , wherein the first portion of pixels are aligned with the green filter pixels, the second portion of pixels are aligned with the blue filter pixels, and the third portion of pixels are aligned with the green filter pixels.

23 . The method of claim 20 , wherein the first portion of pixels are aligned with the blue filter pixels and the green, the second portion of pixels are aligned with the red filter pixels, and the third portion of pixels are aligned with the green filter pixels.

24 . The method of claim 15 , wherein the photosensitive array includes the first portion of pixels and a second portion of pixels.

25 . The method of claim 24 , further comprising:
receiving a first pixel values and a second pixel values from the first portion of pixels; estimating third pixel values for the second portion of pixels from the first pixel values and second pixel values; and wherein the plurality of center of gravity locations are based at least in part on the first pixel values, the second pixel values, and the third pixel values.

26 . The method of claim 24 , wherein the first portion of pixels includes a plurality of blue pixels and a plurality of green pixels.

27 . The method of claim 24 , wherein the projector emits light at a wavelength between 500-520 nm.

28 . A projector, comprising:
an RGB light source operable to project a line of light at one or more predetermined wavelengths.

29 . The projector of claim 28 , wherein the RGB light source is a laser light source.

30 . The projector of claim 29 , wherein the RGB light source has three different diodes.

31 . The projector of claim 28 , wherein the RGB light source includes light emitting diodes.

32 . The projector of claim 28 , whe

Assignees

• Faro Tech Inc

Inventors

• Barba Jacint R
• Wilson Christopher Michael
• Dhasmana Nitesh
• Shen Michael
• Mares Jeremy W
• Macfarlane Keith G
• Fields Randy R
• Atwell Paul C
• Lankalapalli Kishore
• Tohme Yazid

Classifications

• G01B11/2509

  Color coding · CPC title

• G01B11/2513

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title

• G01B11/005 Primary

  coordinate measuring machines · CPC title

• G01J3/513

  having fixed filter-detector pairs · CPC title

• G01B5/008

  using coordinate measuring machines · CPC title