MULTIPLE CHANNEL LOCATING

• US 20130321791A1
• Filed: 08/07/2013
• Published: 12/05/2013
• Est. Priority Date: 07/08/2008
• Status: Active Grant

• Current Assignee: Cognex Corporation
• Original Assignee: Chiaro Technologies LLC (Cognex Corporation)
• Inventors: Feldkhun, Daniel, Moore, Eric Daniel, Braker, Benjamin
• Granted Patent: US 8,836,921 B2
• Time in Patent Office: Days
• US Class Current: 356/4.01
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object
• CPC Class Codes: G01B 11/2527 with phase change by in-plane movement of the patern
• CPC Class Codes: G01B 11/2536 using several gratings with variable grating pitch, projected on the object with the same angle of incidence
• CPC Class Codes: G01C 3/08 Use of electric radiation detectors
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4815 using multiple transmitters
• CPC Class Codes: G01S 7/4818 using optical fibres
• CPC Class Codes: G01S 7/484 Transmitters
• CPC Class Codes: G01S 7/486 Receivers
• CPC Class Codes: G01S 7/499 using polarisation effects

Abstract

Methods, systems, and apparatuses are provided for estimating a location on an object in a three-dimensional scene. Multiple radiation patterns are produced by spatially modulating each of multiple first radiations with a distinct combination of one or more modulating structures, each first radiation having at least one of a distinct radiation path, a distinct source, a distinct source spectrum, or a distinct source polarization with respect to the other first radiations. The location on the object is illuminated with a portion of each of two or more of the radiation patterns, the location producing multiple object radiations, each object radiation produced in response to one of the multiple radiation patterns. Multiple measured values are produced by detecting the object radiations from the location on the object due to each pattern separately using one or more detector elements. The location on the object is estimated based on the multiple measured values.

Claims

1. A method for estimating a location on an object in a three dimensional scene, the method comprising:

producing a plurality of radiation patterns;

measuring at least a portion of two or more of the plurality of radiation patterns at one or more detection locations in space;

producing one or more illumination vectors, each comprising at least a portion of a plurality of illumination values measured at the one or more detection locations in space;

illuminating the location on the object with at least a portion of each of two or more of the plurality of radiation patterns, the illuminated location on the object producing a plurality of object radiations, wherein each object radiation is produced in response to one of the plurality of radiation patterns;

detecting the plurality of object radiations;

producing a plurality of measured values utilizing the plurality of detected object radiations; and

estimating the location on the object based on the plurality of measured values and the one or more illumination vectors.

2. The method of claim 1, wherein measuring at least the portion of two or more of the plurality of radiation patterns at one or more detection locations in space further comprises utilizing one or more detector elements positioned at the one or more detection locations in space.

3. The method of claim 1, further comprising illuminating one or more detection locations on a reference object within a calibration scene with at least a portion of each of two or more of the plurality of radiation patterns, the illuminated location on the reference object producing a plurality of first reference object radiations, wherein each first reference object radiation is produced in response to one of the plurality of radiation patterns;

and

wherein measuring at least the portion of two or more of the plurality of radiation patterns at one or more detection locations in space further comprises;

detecting the plurality of first reference object radiations; and

producing a first illumination vector comprising a plurality of first illumination values utilizing the detected plurality of first reference object radiations.

4. The method of claim 3, wherein the reference object is substantially planar.

5. The method of claim 1, further comprising computing one or more illumination symbols utilizing the one or more illumination vectors.

6. The method of claim 5, wherein the one or more illumination symbols are independent of at least an absolute scaling or an offset of the one or more illumination vectors.

7. The method of claim 5, further comprising computing a detection symbol utilizing the plurality of measured values, and wherein estimating the location on the object comprises comparing the detection symbol to the one or more illumination symbols.

8. The method of claim 7, wherein the one or more illumination symbols for a plurality of detection locations are stored in one or more look-up tables.

9. The method of claim 7, wherein estimating the location on the object comprises determining a nearest neighbor to the measured symbol among the one or more illumination symbols.

10. The method of claim 7, wherein comparing the detection symbol to the one or more illumination symbols utilizes a subset of the illumination symbols.

11. The method of claim 1, further comprising:

altering at least a position of the one or more detection locations in space, a detection configuration, a temperature of a portion of a hardware, an environment of the portion of the hardware, or an operating configuration of the portion of the hardware.

12. The method of claim 11, further comprising

illuminating the location on the reference object within the calibration scene with at least a portion of each of two or more of the plurality of radiation patterns at least during or after the altering, the illuminated location on the reference object producing a plurality of second reference object radiations, wherein each second reference object radiation is produced in response to one of the plurality of radiation patterns;

detecting the plurality of second reference object radiations; and

producing a second illumination vector comprising a plurality of second illumination values utilizing the detected plurality of second reference object radiations.

13. The method of claim 1, wherein two or more of the object radiations are detected jointly.

14. The method of claim 13, further comprising interpreting the two or more jointly detected object radiations as an additional object radiation that is distinct from the plurality of object radiations.

15. The method of claim 14, further comprising altering at least an amplitude, a phase, a position, a direction, a pulse duration, a timing, a polarization, or a wavelength of one or more of the radiation patterns to produce one or more additional radiation patterns.

16. The method of claim 1, further comprising varying at least a projection direction or a projection position of one or more of the plurality of radiation patterns.

17. The method of claim 1, wherein the plurality of measured values for the same location on the object are produced at two or more detection locations.

18. The method of claim 1, further comprising:

illuminating a second location on the object with at least a portion of two or more of the plurality of radiation patterns, the second illuminated location on the object producing a plurality of second object radiations, wherein each second object radiation is produced in response to one of the plurality of radiation patterns, and

detecting the plurality of second object radiations; and

wherein producing the plurality of measured values utilizing the plurality of detected object radiations comprises producing a plurality of measured values utilizing the plurality of detected object radiations and the plurality of detected second object radiations.

19. A method for estimating a location on an object in a three-dimensional scene, the method comprising:

producing a plurality of first radiation patterns;

illuminating the location on the object with a portion of each of two or more of the plurality of first radiation patterns, the illuminated location producing a plurality of first object radiations, wherein each first object radiation is produced in response to one of the plurality of first radiation patterns;

detecting the plurality of first object radiations from the location on the object due to each first radiation pattern separately;

producing a plurality of first measured values based on the plurality of detected first object radiations;

producing a plurality of second radiation patterns;

illuminating the location on the object with a portion of each of two or more of the plurality of second radiation patterns, the illuminated location producing a plurality of second object radiations, wherein each second object radiation is produced in response to one of the plurality of second radiation patterns;

detecting the plurality of second object radiations from the location on the object due to each second radiation pattern separately;

producing a plurality of second measured values based on the plurality of second detected object radiations; and

estimating the location on the object based on the plurality of first measured values and the plurality of second measured values.

20. The method of claim 19, further comprising altering an amplitude, a pulse duration, a timing, a polarization, or a wavelength of one or more of the first radiation patterns to generate one or more of the second radiation patterns.

21. The method of claim 19, wherein one or more multi-channel projectors is utilized to produce the plurality of first radiation patterns and the plurality of second radiation patterns.

22. The method of claim 19, wherein two or more of the first object radiations or the second object radiations are detected jointly.

23. The method of claim 22, further comprising interpreting the two or more jointly detected object radiations as an additional object radiation that is distinct from the one or more first object radiations or second object radiations.

24. The method of claim 23, further comprising altering at least an amplitude, a phase, a position, a direction, a pulse duration, a timing, a polarization, or a wavelength of one or more of the first radiation patterns or the second radiation patterns to produce one or more additional radiation patterns.

25. The method of claim 19, further comprising varying at least a projection direction or a projection position of one or more of the first radiation patterns or the second radiation patterns.

26. The method of claim 19, wherein at least the first measured values or the second measured values of at least the first object radiations or the second object radiations for the same location on the object are produced at two or more detection locations.

27. The method of claim 19, further comprising repeating one or more of the following:

utilizing one or more modified radiation patterns, the producing of a plurality of radiation patterns, the illuminating of the location of the object, the detecting of a plurality of object radiations, and the producing of a plurality of measured values.

28. A system for estimating a location on an object in a three dimensional scene, the system comprising:

one or more radiation pattern projectors configured to at least;

produce a plurality of radiation patterns; and

illuminate the location on the object with at least a portion of each of two or more of the plurality of radiation patterns, the illuminated location on the object producing a plurality of object radiations, wherein each object radiation is produced in response to one of the plurality of radiation patterns;

or

produce a plurality of first radiation patterns;

illuminate the location on the object with a portion of each of two or more of the plurality of first radiation patterns, the illuminated location producing a plurality of first object radiations, wherein each first object radiation is produced in response to one of the plurality of first radiation patterns;

produce a plurality of second radiation patterns; and

illuminate the location on the object with a portion of each of two or more of the plurality of second radiation patterns, the illuminated location producing a plurality of second object radiations, wherein each second object radiation is produced in response to one of the plurality of second radiation patterns;

one or more detectors configured to at least;

measure at least a portion of two or more of the plurality of radiation patterns at one or more detection locations in space;

produce one or more illumination vectors, each comprising at least a portion of a plurality of illumination values measured at the one or more detection locations in space;

detect the plurality of object radiations; and

produce a plurality of measured values utilizing the plurality of detected object radiations;

or

detect the plurality of first object radiations from the location on the object due to each first radiation pattern separately;

produce a plurality of first measured values based on the plurality of detected first object radiations;

detect the plurality of second object radiations from the location on the object due to each second radiation pattern separately; and

produce a plurality of second measured values based on the plurality of second detected object radiations; and

one or more processors configured to at least;

estimate the location on the object based on the plurality of measured values and the one or more illumination vectors;

or

estimate the location on the object based on the plurality of first measured values and the plurality of second measured values.

29. The system of claim 28, wherein the one or more radiation pattern projectors comprises one or more multi-channel projectors.

30. The system of claim 28, wherein one or more detectors configured to measure at least the portion of two or more of the plurality of radiation patterns at one or more detection locations in space are further configured to utilize one or more detector elements positioned at the one or more detection locations in space.

31. The system of claim 28, wherein the one or more radiation pattern protectors is further configured to illuminate one or more detection locations on a reference object within a calibration scene with at least a portion of each of two or more of the plurality of radiation patterns, the illuminated location on the reference object producing a plurality of first reference object radiations, wherein each first reference object radiation is produced in response to one of the plurality of radiation patterns;

and the one or more detectors configured to measure at least the portion of two or more of the plurality of radiation patterns at one or more detection locations in space are further configured to;

detect the plurality of first reference object radiations; and

produce a first illumination vector comprising a plurality of first illumination values utilizing the detected plurality of first reference object radiations.