Wireless methods and systems for three-dimensional non-contact shape sensing

• US 7,256,899 B1
• Filed: 10/04/2006
• Issued: 08/14/2007
• Est. Priority Date: 10/04/2006
• Status: Active Grant

• Current Assignee: Patent Armory Inc.
• Original Assignee: Ivan Faul
• Inventors: Faul, Ivan, Schulz, Waldean Allen
• Primary Examiner(s): Nguyen; Sang H.
• Application Number:
  US11/538,753
• Time in Patent Office: 314 Days
• Field of Search: 356603-640, 382/154, 382/293, 382/106, 345/420, 348/169, 348/180
• US Class Current: 356/623
• CPC Class Codes: G01B 11/2522 the position of the object changing and being recorded
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects

Abstract

Methods for acquiring an approximation of the surface geometry of a 3-dimensional object include projecting pattern of structured light on the object, moving the pattern with respect to the object, acquiring images of the intersection of the light on the object over time, determining local coordinates of points on the intersection with respect to the pattern, tracking the position of the pattern, transforming the local coordinates to object coordinates, and accumulating the points as a model of the surface of the object. The methods include a step for wirelessly and possibly compactly transmitting geometrical data which characterizes an intersection for a given position of the scanner with respect to the object. Systems for embodying the method include a self-powered wireless, non-contact optical scanner, the location and orientation of which may be tracked with respect to an object coordinate system.

Claims

1. A method for acquiring an approximation of a surface geometry of a 3-dimensional object comprising:

establishing an object coordinate system in known relationship to the object;

projecting a pattern of structured light of known geometry onto the object;

forming an image of an intersection of the pattern of structured light with the object;

processing the image to generate a set of data characterizing the intersection relative to a position of the pattern of structured light;

wirelessly transmitting some portion of the image and intersection data to a receiver;

receiving the transmitted portion of the image and intersection data;

tracking the position of the pattern of structured light;

associating each intersection datum with the position of the projected pattern of light at the time the image corresponding to the datum was formed;

transforming each intersection datum into coordinates of the object coordinate system; and

accumulating the transformed coordinates to form an approximation of the surface of the object.

2. The method of claim 1, wherein the projecting of the pattern of light projects a narrow ray-like beam of light.

3. The method of claim 1, wherein the projecting of the pattern of light projects a planar fan of light.

4. The method of claim 1, wherein the image processing excludes all video data from the transmitted intersection data, except data characterizing the image of intersection.

5. The method of claim 1, wherein the position tracking utilizes triangulation calculation.

6. The method of claim 1, wherein the processing of the image generates 3D coordinates of one or more points in the intersection relative to a coordinate system in known relationship to the projected pattern of structured light.

7. The method of claim 1, wherein the processing of the image generates 3D coordinates of one or more points in the intersection relative to a coordinate system in known relationship to the image.

8. The method of claim 1, wherein the processing of the image generates 2D coordinates of one or more points in the image of the intersection.

9. The method of claim 8, wherein 3D coordinates of one or more points in the intersection are computed after receiving the 2D coordinates.

10. The method of claim 1, wherein the intersection data is transmitted using an industry standard communication protocol.

11. The method of claim 1, wherein the intersection data is transmitted using a proprietary data communication protocol.

12. The method of claim 1, wherein the position of the projected pattern of structured light is tracked by tracking at least one position indicator on an assembly which houses a source of the projected pattern of light.

13. The method of claim 1, further comprising the step of generating a tessellation of patches representing the surface of the object based on accumulated transformed coordinates.

14. The method of claim 1, wherein the intersection data includes a representation of the color of at least one point on the surface of the object.

15. The method of claim 1, further comprising a step of wirelessly transmitting to a receiving workstation the transformed coordinates which form an approximation of the surface of the object.

16. A system for acquiring an approximation of a surface geometry of a 3-dimensional object comprising:

means for establishing an object coordinate system in known relationship to the object;

means for projecting a pattern of structured light of known geometry onto the object;

means for forming an image of an intersection of the pattern of structured light with the object;

processing means for generating a set of data characterizing the intersection relative to a position of the pattern of light;

transmitting means for transmitting some portion of the image or intersection data to a receiver;

receiving means for receiving the transmitted processed intersection data;

tracking means for tracking the position of the projected pattern of structured light;

means for associating each intersection datum with the position of the projected pattern of light at the time the image corresponding to the datum was formed;

transforming means for transforming each intersection datum into coordinates of the object coordinate system; and

accumulating means for accumulating the transformed coordinates to form a model approximating the surface geometry of the object.