Three-dimensional imager

Patent metadata

Field	Value
Publication number	US-10907955-B2
Application number	US-201916518135-A
Country	US
Kind code	B2
Filing date	Jul 22, 2019
Priority date	Aug 19, 2015
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

A three-dimensional (3D) measuring system and a method of determining a distance is provided. A three-dimensional (3D) measuring system includes a master part having a first base part and a first part-under-test including a second base. A photogrammetry camera images the master part to generate two-dimensional (2D) images. A first 3D imager determines 3D coordinates in a first imager frame of reference. A second 3D imager determines 3D coordinates in a second imager frame of reference. The system determines in a system frame of reference a first pose of the first imager and a second pose of the second imager. The system is further configured to determine 3D coordinates of the first part-under-test in the system frame of reference.

First claim

What is claimed is:

1. A three-dimensional (3D) measuring system comprising:
a master part including a first base part selected from a plurality of base parts, there being at least three fiducial markers affixed to the first base part;
a first part-under-test including a second base part selected from the plurality of base parts;
a photogrammetry camera configured to image the master part, including the at least three fiducial markers, from a plurality of photogrammetry camera positions to obtain a corresponding plurality of photogrammetry two-dimensional (2D) images;
a first 3D imager having a first projector and a first camera, the first 3D imager configured to determine 3D coordinates in a first imager frame of reference;
a second 3D imager having a second projector and a second camera, the second 3D imager configured to determine 3D coordinates in a second imager frame of reference,
wherein the system is configured to determine in a system frame of reference a first pose of the first 3D imager and a second pose of the second 3D imager based at least in part on the plurality of photogrammetry 2D images, determined 3D coordinates of at least three fiducial markers from among the at least three fiducial markers in the first imager frame of reference, and determined 3D coordinates of at least three fiducial markers from among the at least three fiducial markers in the second imager frame of reference, and
wherein the system is further configured to determine 3D coordinates of the first part-under-test in the system frame of reference based at least in part on the determined first pose, the determined second pose, determined 3D coordinates of the first part-under-test by the first 3D imager in the first imager frame of reference, and determined 3D coordinates of the first part-under-test by the second 3D imager in the second imager frame of reference.

2. The system of claim 1 , further comprising:
a scale bar having a first target and a second target, a distance between the first target and the second target being a calibrated reference distance, the scale bar being configured to be fixedly positioned relative to the master part, the first target and the second target being visible in the plurality of photogrammetry 2D images,
wherein the system if further configured to determine the first pose and the second pose based on the calibrated reference distance.

3. The system of claim 1 , wherein the three fiducial markers include retroreflective targets and the photogrammetry camera further includes a flash unit configured to illuminate the retroreflector targets.

4. The system of claim 1 , wherein the at least two of the plurality of photogrammetry 2D images are obtained with the photogrammetry camera rotated to different orientations.

5. The system of claim 1 , wherein:
the first 3D imager further includes a processor configured to determine the 3D coordinates in the first imager frame of reference, and is further configured to cooperate with an external computer to determine the 3D coordinates in the first imager frame of reference; and
the second 3D imager further includes a processor configured to determine the 3D coordinates in the second imager frame of reference, and is further configured to cooperate with the external computer to determine the 3D coordinates in the second imager frame of reference,
wherein the system is further configured to cooperate with an external computer to determine in the system frame of reference the first pose of the first 3D imager and the second pose of the second 3D imager.

6. The system of claim 1 , wherein the system further comprises:
a second part-under-test including a third base part selected from the plurality of base parts,
wherein the system is further configured to determine 3D coordinates of the second part-under-test in the system frame of reference based at least in part on the determined first pose, the determined second pose, determined 3D coordinates of the second part-under-test by the first 3D imager in the first imager frame of reference, and determined 3D coordinates of the second part-under-test by the second 3D imager in the second imager frame of reference.

7. The system of claim 1 , wherein:
the at least three fiducial markers from among the at least three fiducial markers in the first imager frame of reference includes at least one fiducial marker not included in the at least three fiducial markers from among the at least three fiducial markers in the second imager frame of reference, and
the at least three fiducial markers includes a first marker, a second marker, a third marker, a fourth marker, a fifth marker, and a sixth marker, the at least three fiducial markers from among the at least three fiducial markers in the first imager frame of reference including the first marker, the second marker, and the third marker but not the fourth marker, the fifth marker or the sixth marker, the at least three fiducial markers from among the at least three fiducial markers in the second imager frame of reference including the fourth marker, the fifth marker, and the sixth marker but not the first marker, the second marker, or the third marker.

8. A method comprising:
providing a master part, a first part-under-test, a photogrammetry camera, a first three-dimensional (3D) imager, and a second 3D imager, the master part including a first base part selected from a plurality of base parts, there being at least three fiducial markers affixed to the first base part, the first part-under-test including a second base part selected from the plurality of base parts, the first 3D imager having a first projector, a first camera, and a first frame of reference, the second 3D imager having a second projector, a second camera, and a second frame of reference;
imaging the master part, including the at least three fiducial markers, with the photogrammetry camera from a plurality of photogrammetry camera positions to obtain a corresponding plurality of photogrammetry two-dimensional (2D) images;
determining with the first 3D imager 3D coordinates of the at least three fiducial markers in the first frame of reference;
determining with the second 3D imager 3D coordinates of the at least three fiducial markers in the second frame of reference;
determining in a system frame of reference a first pose of the first 3D imager and a second pose of the second 3D imager based at least in part on the plurality of photogrammetry 2D images, the determined 3D coordinates of at least three fiducial markers from among the at least three fiducial markers in the first frame of reference, and the determined 3D coordinates of at least three fiducial markers from among the at least three fiducial markers in the second frame of reference;
determining with the first 3D imager first 3D coordinates of the first part-under-test in the first frame of reference;
determining with the second 3D imager second 3D coordinates of the first part-under-test in the second frame of reference;
determining 3D coordinates of the first part-under-test in the system frame of reference based at least in part on the determined first pose, the determined second pose, the determined first 3D coordinates of the first part-under-test in the first imager frame of reference, and the determined second 3D coordinates of the first part-under-test in the second frame of reference; and
storing the 3D coordinates of the first part-under-test in the system frame of reference.

9. The method of claim 8 , further comprising:
providing a scale bar having a first target and a second target, a distance between the first target and the second target being a calibrated reference distance, the scale bar being configured to be fixedly positioned relat

Assignees

• Faro Tech Inc

Inventors

• Armstrong Matthew
• Garcia Christopher S
• Hordeski Jr Theodore J
• Veksland Michael
• Vinshtok Yevgeniy

Classifications

• H04N13/239 Primary

  using two two-dimensional [2D] image sensors having a relative position equal to or related to the interocular distance (H04N13/243 takes precedence) · CPC title

• G01B11/245

  using a plurality of fixed, simultaneously operating transducers ({G01B11/2408 - G01B11/2425, } G01B11/255 take precedence) · CPC title

• G01C3/10

  using a parallactic triangle with variable angles and a base of fixed length in the observation station, e.g. in the instrument · CPC title

• H04N2013/0081

  Depth or disparity estimation from stereoscopic image signals · CPC title

• G01C3/08

  Use of electric radiation detectors · CPC title