Transprojection of geometry data

• US 8,229,208 B2
• Filed: 04/02/2010
• Issued: 07/24/2012
• Est. Priority Date: 01/14/2004
• Status: Active Grant

• Current Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Original Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Inventors: Pulla, Sandeep, Eaton, Homer
• Primary Examiner(s): Le, Brian Q
• Assistant Examiner(s): Torres, Jose M
• Application Number:
  US12/753,720
• Publication Number:
  US 20100272348A1
• Time in Patent Office: 844 Days
• Field of Search: 382152-154, 335/03, 702/85
• US Class Current: 382/154
• CPC Class Codes: G01B 21/02 for measuring length, width, or thickness G01B21/10 takes precedence
• CPC Class Codes: G01B 21/04 by measuring coordinates of points
• CPC Class Codes: G01B 9/02023 Indirect probing of object, e.g. via influence on cavity or fibre
• CPC Class Codes: G01B 9/02029 Combination with non-interferometric systems, i.e. for measuring the object
• CPC Class Codes: G01B 9/0203 With imaging systems
• CPC Class Codes: G01B 9/02031 With non-optical systems, e.g. tactile
• CPC Class Codes: G01B 9/0205 of probe head
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

Systems and methods for transprojection of geometry data acquired by a coordinate measuring machine (CMM). The CMM acquires geometry data corresponding to 3D coordinate measurements collected by a measuring probe that are transformed into scaled 2D data that is transprojected upon various digital object image views captured by a camera. The transprojection process can utilize stored image and coordinate information or perform live transprojection viewing capabilities in both still image and video modes.

Claims

1. A method for displaying geometry and imaging information using a coordinate measuring machine, the method comprising:

acquiring at least one first image of at least a portion of a target area with an imaging device mounted on the coordinate measuring machine;

mapping points of the first image to corresponding points in the target area using a probe mounted on the coordinate measuring machine such that the probe is movable with the imaging device;

processing the at least one first image and the mapped points of the first image to determine one or more calibration parameters that relates a target coordinate system associated with the target area to a first image coordinate system associated with the first image;

acquiring geometry information for an object;

acquiring at least one second image of the object, distinct from the at least one first image;

performing a transformation operation using at least one of the one or more calibration parameters determined from the at least one first image to map the geometry information of the object to the second image; and

displaying the second image overlaid with the geometry information.

2. The method for displaying geometry and imaging information of claim 1, further comprising:

associating a second image coordinate system with the second image and a target coordinate system with the target area;

using the at least one calibration parameter to relate the second image coordinate system to the target coordinate system; and

applying the at least one calibration parameter to the geometry information of the object to transform the geometry information such that the second image is overlaid with the geometry information accurately reflecting the position and characteristics of geometry information in the context of the second image.

3. The method for displaying geometry and imaging information of claim 2 wherein, the second image coordinate system is two dimensional and the target coordinate system is three dimensional and the at least one calibration parameter relates three dimensional points of the target coordinate system to two dimensional points of the second image coordinate system.

4. The method for displaying geometry and imaging information of claim 3 wherein, the geometry information is three dimensional and the second image is two dimensional and the transformation operation maps the three dimensional geometry information to the two dimensional image.

5. The method for displaying geometry and imaging information of claim 2 wherein, the second image coordinate system is three dimensional and the target coordinate system is three dimensional and the at least one calibration parameter relates three dimensional points of the target coordinate system to three dimensional points of the second image coordinate system.

6. The method for displaying geometry and imaging information of claim 5 wherein, the geometry information is three dimensional and the second image is three dimensional and the transformation operation maps the three dimensional geometry information to the three dimensional image.

7. The method for displaying geometry and imaging information of claim 2 wherein, the at least one calibration parameter is identified by:

designating at least one calibration target having a known positional relationship to the target area, wherein the at least one first image contains a representation of the at least one calibration target;

applying a target detection operation to discern the representation of the at least one calibration target within the at least one first image;

associating the target'"'"'s known positional relationship to the target area with the target coordinate system;

associating the representation of the at least one calibration target with the second image coordinate system; and

developing the at least one calibration parameter to relate the target coordinate system and image coordinate system on the basis of the target and its representation in the two coordinate systems.

8. The method for displaying geometry and imaging information of claim 7 wherein, the target detection functionality discerns the representation of the at least one calibration target based on at least one target characteristic selected from the group consisting of:

shape, size, coloration, location, luminosity, brightness, and contrast.

9. The method for displaying geometry and imaging information of claim 8 wherein, the at least one target characteristic is evaluated for at least one selected seed pixel of the first image and a search is performed to identify other pixels associated with the calibration target.

10. The method for displaying geometry and imaging information of claim 9 wherein, the pixel identification search comprises a recursive search performed in the vicinity of the at least one selected seed pixel.

11. The method for displaying geometry and imaging information of claim 1 wherein, the geometry information relates to an object at least partially contained within the target area and the second image contains a representation of at least a portion of the object which are displayed to accurately reflect scaled coordinate details of the object in the perspective of the second image.

12. The method for displaying geometry and imaging information of claim 1 wherein, the coordinate measuring machine is an articulated arm coordinate measuring machine and the geometry information is acquired using the probe, wherein the probe is affixed to the articulated arm coordinate measuring machine, the articulated arm coordinate measuring machine being capable of being positioned about the target area.

13. The method for displaying geometry and imaging information of claim 12 wherein, the probe comprises a coordinate acquisition device selected from the group consisting of:

a contact-sensitive probe, a remote-scanning probe, a laser- scanning probe, a probe that uses a strain gauge for contact detection, a probe that uses a pressure sensor for contact detection, a probe that used an infrared beam for positioning, and a probe configured to be electrostatically-responsive.

14. The method for displaying geometry and imaging information of claim 12 wherein, a plurality of second images are acquired from various perspectives and selected second images and geometry information are displayed on the basis of the probe location about the target area.

15. The method for displaying geometry and imaging information of claim 14 wherein, the second image and geometry information to be displayed are determined by identifying the second image closest in perspective to the target area view from the current probe position.

16. The method for displaying geometry and imaging information of claim 15 wherein, each second image is associated with geometry information characterizing the perspective from which the second image was acquired.

17. The method for displaying geometry and imaging information of claim 16 wherein, second images and geometry information to be displayed are identified on the basis of a coordinate range associated with each second image such that when the probe is positioned substantially within the coordinate range, the second image for the coordinate range and corresponding geometry information are displayed.

18. The method for displaying geometry and imaging information of claim 1 wherein, the second image and geometry information are displayed based upon at least one second image characteristic.

19. The method for displaying geometry and imaging information of claim 18 wherein, the at least one second image characteristic is selected from the group consisting of:

magnification, perspective, orientation, and view.

20. The method for displaying geometry and imaging information of claim 1 wherein, a processing operation is performed to the second image and corresponding geometry information to achieve a selected perspective or view of the second image.

21. The method for displaying geometry and imaging information of claim 20 wherein, the processing operation is selected from the group consisting of:

realignment, rotation, skew, cropping, and zooming.

22. The method for displaying geometry and imaging information of claim 1 wherein, the second image is acquired using an imaging member comprising a camera capable of generating still images or video images.

23. The method for displaying geometry and imaging information of claim 1 wherein, the second image is acquired using an imaging device selected from the group consisting of:

X-ray imaging devices, ultrasonic imaging devices, laser imaging devices, infrared imaging devices, optical imaging devices, and digital imaging devices.

24. The system of claim 1, wherein the imaging device is mounted on the coordinate measuring machine near the probe.

25. A system for coordinate acquisition and visualization, the system comprising:

an arm member having a probe member attached thereto, the arm member positioned with respect to a target area such that the probe member acquires coordinate information from the target area;

an imaging member attached to the arm member and moveable with the probe member, and configured to generate at least one second image of at least a portion of the target area; and

a controller configured to receive the coordinate information and the at least one second image whereupon the controller adjusts and overlays the coordinate information upon the at least one second image to reflect the position and orientation of the coordinate information in the context of the second image using at least one calibration parameter,

wherein the calibration parameter is determined using a first image and mapped points of the first image acquired using the arm member, the first image being generated prior to the generation of the at least one second image and distinct from the at least one second image.

26. The system for coordinate acquisition and visualization of claim 25 wherein, the arm member moveably positions the probe member about the target area.

27. The system for coordinate acquisition and visualization of claim 26 wherein, the arm member is articulated and moveable about at least one axis to position the probe member in a plurality of orientations with respect to the target area.

28. The system of claim 25, wherein the imaging member is attached to the arm member near the probe member.