Device for optically scanning and measuring an environment

Patent metadata

Field	Value
Publication number	US-9858682-B2
Application number	US-201715463144-A
Country	US
Kind code	B2
Filing date	Mar 20, 2017
Priority date	Dec 14, 2012
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A device for optically scanning and measuring an environment is provided. The device includes at least one projector for producing at least one uncoded pattern on an object in the environment. A first camera is provided for recording at least one first image of the object provided with the pattern, the first camera having a first image plane. A second camera is provided for recording at least one second image of the object provided with the uncoded pattern, the second camera being spaced apart from the first camera in order to acquire the uncoded pattern on a second image plane. A controller is provided having a processor configured to determine the three-dimensional coordinates of points on the surface of the object based at least in part on the uncoded pattern, the at least one first image and the at least one second image.

First claim

The invention claimed is:

1. A system for optically scanning and measuring an object in an environment, the system comprising:
a scanner device that includes a projector, a first camera, and a second camera positioned in a predetermined geometrical arrangement;
the projector projecting during operation a first pattern of light that is comprised of a first regular pattern of identical light points in a grid, the projector having a projector optical axis;
the first camera records in operation, in a first time instance, a first image of the first pattern of light projected on the object, the first camera having a first camera optical axis;
the second camera records in operation, in the first time instance, a second image of the first pattern of light projected onto the object, the second camera having a second camera optical axis;
each of the illuminated light points corresponding to and lying on an epipolar lines in each of two of an image or a projector plane associated with the first camera, the second camera and the projector, the correspondence among epipolar lines and the illuminated light points on the image or projector planes being based on geometrical epipolar relations between the image or projector planes; and
a processor operably coupled to the projector, the first camera and the second camera, the processor determines in operation a correspondence among each of the illuminated light points on the image or projector planes based at least in part by the epipolar relations, the processor further determining in operation three-dimensional coordinates of each of the illuminated light points on the object based at least in part on a density of the illuminated light points in the first pattern of light, the first image of the first pattern of light on the object, the second image of the first pattern of light on the object, and the geometrical arrangement of the projector, the first camera, and the second camera.

2. The system of claim 1 wherein the collection of illuminated first regular pattern of identical light points includes at least three illuminated spots, each of the illuminated spots including a bright region surrounded by a dark region, each illuminated spot being separate from any other illuminated spot.

3. The system of claim 2 wherein the collection of illuminated first regular pattern of identical light points further includes an illuminated line, the illuminated line including a continuous linear region of illumination.

4. The system of claim 1 , wherein:
the projector includes a laser that emits a first wavelength to create the first pattern of light; and
the first camera and the second camera include bandpass filters that transmit at the first wavelength.

5. The system of claim 1 wherein the scanner device further comprises a third camera, the third camera being a color camera that records images of the object at visible wavelengths, the third camera being fixed on the scanner device.

6. The system of claim 1 wherein the scanner device generates a second pattern of light, the second pattern of light being different than and offset from the first pattern of light.

7. The system of claim 6 , wherein during operation the second pattern of light interferes with the first pattern of light.

8. The system of claim 1 , wherein during operation the processor causes the projector to project one of a plurality of patterns, each of the plurality of patterns being projected in a predetermined sequence.

9. The system of claim 8 wherein during operation the projector projects a second pattern of light, the second pattern of light being offset with respect to time to the first pattern of light, the second pattern of light being a second pattern comprised of identical light points in a grid, the first pattern being different than the second pattern.

10. The system of claim 9 , wherein the first pattern has a first density of points and the second pattern has a second density of points, the first density being different than the second density.

11. The system of claim 9 , wherein the first pattern has a first intensity and the second pattern has a second intensity, the first intensity being different than the second intensity.

12. The system of claim 1 , wherein the first pattern of light further comprises a second pattern of light, the first pattern of light having a first optical wavelength and the second pattern of light having a second optical wavelength different than the first wavelength, the second pattern of light being a second pattern comprised of identical light points in a grid.

13. The system of claim 1 , further comprising a second projector separate from the scanner device, the second projector projects in operation a stationary second pattern of light.

14. The system of claim 13 wherein the scanner device movable relative to the second projector.

15. The system of claim 14 , wherein during operation:
the first camera acquires a plurality of images, each of the plurality of images including the first pattern and the second pattern on the object; and
the processor registers the each of the plurality of images relative to each other based at least in part on the second pattern.

16. The system of claim 14 , wherein the second pattern of light is different from the first pattern of light with regard to geometry, time, light spectrum or a combination thereof.

17. The system of claim 14 , wherein the second projector is movable relative to the scanner device.

18. The system of claim 1 , wherein the collection of illuminated first regular pattern of identical light points includes a first plurality of light points having a first intensity and a second pattern of light having a second plurality of light points having a second intensity different than the first intensity, wherein the first plurality of light points and the second plurality of light points each define a multivalued uncoded structured light pattern.

Assignees

• Faro Tech Inc

Inventors

• Heidemann Rolf
• Ossig Martin
• Becker Reinhard

Classifications

• G01B11/002

  for measuring two or more coordinates · CPC title

• G06T7/593 Primary

  from stereo images · CPC title

• G01B11/2513 Primary

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

• H04N13/0242

  Electricity · mapped topic

• G06T7/521

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title