Virtual laser projection system and method

• US 9,410,793 B2
• Filed: 08/06/2014
• Issued: 08/09/2016
• Est. Priority Date: 08/06/2013
• Status: Active Grant

• Current Assignee: Faro Technologies Incorporated
• Original Assignee: Laser Projection Technologies, Inc. (Faro Technologies Incorporated)
• Inventors: Kaufman, Steven P., Savikovsky, Arkady, Mohazzab, Masoud
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Ahmed, Jamil
• Application Number:
  US14/453,390
• Publication Number:
  US 20150043011A1
• Time in Patent Office: 734 Days
• US Class Current: 1/1
• CPC Class Codes: B05C 21/005 Masking devices stencils B05C17/06; masking devices for which the means for applying liquids or other fluent material is spraying or is not important B05B12/20
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01B 11/245 using a plurality of fixed, simultaneously operating transducers G01B11/2408 - G01B11/2425, G01B11/255 take precedence
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A virtual laser projection system and method includes one or more measuring laser projectors, one or more non-measuring laser projectors, an array of reference targets, and a computing system. The one or more measuring laser projectors and one or more non-measuring laser projectors operate under common control of the computing system to register their respective locations using the array of reference targets, detect and locate features of a work object to be illuminated, convert all location information into a common coordinate system, and illuminate the work object with laser light beams using the common coordinate system.

Claims

1. A laser projection system for projecting image data onto a surface of a work object, the system comprising:

an array of reference targets spaced from, and not in direct contact with, the work object;

a measuring laser projector;

at least one non-measuring laser projector different from the measuring laser projector; and

a computer having one or more processors configured to;

cause the measuring laser projector to direct a first laser light beam at a subset of the targets in the array of reference targets;

cause the measuring laser projector to receive reflected light from the subset of the targets in the array of reference targets;

register the measuring laser projector with respect to a first coordinate system based on the received reflected light, the first coordinate system is a coordinate system associated with the array of reference targets and is external to the work object;

cause the measuring laser projector to direct a second laser light beam onto the work object surface;

cause the measuring laser projector to receive diffusely reflected light from the work object surface;

detect a plurality of features of the work object surface based on the received diffusely reflected light;

determine the locations of the plurality of features with respect to the first coordinate system;

obtain the locations of the plurality of features with respect to a second coordinate system different from the first coordinate system, the second coordinate system being the work object coordinate system;

determine the locations of the plurality of features and the at least one non-measuring laser projector in a common coordinate system; and

cause the at least one non-measuring laser projector to project the image data onto the work object surface based on the locations of the plurality of features and the location of the at least one non-measuring laser projector in the common coordinate system.

2. The system of claim 1, wherein the array of reference targets comprises retro-reflectors.

3. The system of claim 1, wherein the one or more processors are further configured to:

cause the at least one non-measuring laser projector to direct a third laser light beam at a second subset of the targets in the array of reference targets;

cause the at least one non-measuring laser projector to receive reflected light from the second subset of targets in the array of reference targets; and

register the at least one non-measuring laser projector with respect to the first coordinate system.

4. The system of claim 1, wherein the one or more processors are further configured to cause the measuring laser projector to project image data onto the work object surface.

5. The system of claim 1, wherein the at least one non-measuring laser projector includes at least one of the reference targets of the array of reference targets coupled to a support structure supporting the at least one non-measuring laser projector in position.

6. The system of claim 1, wherein at least one of the measuring laser projector and the at least one non-measuring laser projector is mounted on a moveable cart.

7. The system of claim 1, wherein the position of at least a subset of reference targets in the array of reference targets is fixed within a work cell and the first coordinate system is a coordinate system associated with the work cell.

8. The system of claim 1, wherein the position of the array of reference targets is movable within a work cell.

9. The system of claim 1, wherein the common coordinate system is the first coordinate system, and determining the locations of the plurality of features and the at least one non-measuring laser projector in the common coordinate system comprises converting coordinates of the plurality of features in the second coordinate system into coordinates in the first coordinate system.

10. The system of claim 1, wherein the common coordinate system is the second coordinate system, and determining the locations of the plurality of features and the at least one non-measuring laser projector in the common coordinate system comprises converting coordinates of the at least one non-measuring laser projector in the first coordinate system into coordinates in the second coordinate system.

11. A method for projecting image data onto a surface of a work object, the method comprising:

directing a first laser light beam from a measuring laser projector at a subset of targets in an array of reference targets spaced from, and not in direct contact with, the work object;

receiving the reflected light from the subset of targets in the array of reference targets at the measuring laser projector;

registering the location of the measuring laser projector with respect to a first coordinate system based on the received reflected light, the first coordinate system is a coordinate system associated with the array of reference targets and is external to the work object;

directing a second laser light beam from the measuring laser projector at the work object surface;

receiving diffusely reflected light from the work object surface at the measuring laser projector;

detecting a plurality of features of the work object surface based on the diffusely reflected light;

determining the locations of the plurality of features with respect to the first coordinate system;

obtaining the locations of the plurality of features with respect to a second coordinate system different from the first coordinate system, the second coordinate system being the work object coordinate system;

determining the locations of the plurality of features and at least one non-measuring laser projector different from the measuring laser projector in a common coordinate system; and

projecting the image data onto the work object surface based on the locations of the plurality of features and the location of the at least one non-measuring laser projector in the common coordinate system.

12. The method of claim 11, wherein the array of reference targets comprises retro-reflectors.

13. The method of claim 11, further comprising:

directing a third laser light beam at a second subset of targets in the array of reference targets using the at least one non-measuring laser projector;

receiving reflected light from the second subset of targets in the array of reference targets at the at least one non-measuring laser projector; and

registering the at least one non-measuring laser projector with respect to the first coordinate system.

14. The method of claim 11, further comprising:

projecting the image data onto the work object surface using the measuring laser projector.

15. The method of claim 11, wherein the at least one non-measuring laser projector includes at least one of the reference targets of the array of reference targets coupled to support structure supporting the at least one non-measuring laser projector in position.

16. The method of claim 11, wherein at least one of the measuring laser projector and the at least one non-measuring laser projector is mounted on a moveable cart.

17. The method of claim 16, wherein the image data corresponds to a paint mask, and wherein the method further comprises removing at least one of the measuring laser projector, the array of reference targets, and the at least one non-measuring laser projector from a work cell after the paint mask is applied, and before paint is applied.

18. The method of claim 11, wherein the position of at least a subset of the reference targets in the array of reference targets is fixed within a work cell, and the first coordinate system is a coordinate system associated with the work cell.

19. The method of claim 11, wherein the common coordinate system is the first coordinate system, and determining the locations of the plurality of features and the at least one non-measuring laser projector in the common coordinate system comprises converting coordinates of the plurality of features in the second coordinate system into coordinates in the first coordinate system.

20. The method of claim 11, wherein the common coordinate system is the second coordinate system, and determining the locations of the plurality of features and the at least one non-measuring laser projector in the common coordinate system comprises converting coordinates of the at least one non-measuring laser projector in the first coordinate system into coordinates in the second coordinate system.