Optical navigation apparatus using fixed beacons and a centroid sensing device

• US 20070211239A1
• Filed: 10/31/2006
• Published: 09/13/2007
• Est. Priority Date: 03/08/2006
• Status: Active Grant

• Current Assignee: Electronic Scripting Products, Inc.
• Original Assignee: Electronic Scripting Products, Inc.
• Inventors: Mandella, Michael J., Alboszta, Marek, Gonzalez-Banos, Hector H., Hawks, Timothy J.
• Granted Patent: US 7,729,515 B2
• Time in Patent Office: Days
• US Class Current: 356/138
• CPC Class Codes: G06F 3/0325 using a plurality of light emitters or reflectors or a plurality of detectors forming a reference frame from which to derive the orientation of the object, e.g. by triangulation or on the basis of reference deformation in the picked up image
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0423 using sweeping light beams, e.g. using rotating or vibrating mirror
• CPC Class Codes: G06F 3/0425 using a single imaging device like a video camera for tracking the absolute position of a single or a plurality of objects with respect to an imaged reference surface, e.g. video camera imaging a display or a projection screen, a table or a wall surface, on which a computer generated image is displayed or projected tracking a projected light spot to determine a position on a display surface G06F3/0386
• CPC Class Codes: G06F 3/0428 by sensing at the edges of the touch surface the interruption of optical paths, e.g. an illumination plane, parallel to the touch surface which may be virtual sensing beam interruptions in a planar beam grid of an optical touch-screen G06F3/0421
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

The present invention relates to an optical navigation system for determining at least one parameter of a pose, which includes the position and orientation of an object in an environment. The optical navigation system uses a number of beacons affixed at known locations in the environment to provide electromagnetic radiation in a sequenced pattern. An on-board optic images the radiation from the beacons onto an on-board centroid sensing device to obtain an imaged distribution of the radiation on the on-board centroid sensing device. The centroid sensing device determines the centroid of the imaged distribution and provides centroid information to a navigation unit for determining at least one parameter of the pose of the object from the centroid. The navigation system is particularly well-suited for navigating hand-held objects.

Claims

1. An optical navigation system for determining at least one parameter of a pose of an object in an environment, said optical navigation system comprising:

a) a plurality of beacons at predetermined locations in said environment for providing an electromagnetic radiation in a sequenced pattern;

b) an on-board optic for imaging said electromagnetic radiation onto an on-board centroid sensing device for determining a centroid of an imaged distribution of said electromagnetic radiation;

c) a navigation unit for determining said at least one parameter of said pose from said centroid.

2. The optical navigation system of claim 1, wherein said sequenced pattern is a modulated sequenced pattern.

3. The optical navigation system of claim 2, wherein said navigation unit comprises a mechanism for adjusting said sequenced pattern based on said at least one parameter of said pose.

4. The optical navigation system of claim 2, wherein said sequenced pattern comprises amplitude modulation of said plurality of beacons.

5. The optical navigation system of claim 2, wherein said sequenced pattern comprises frequency modulation of said plurality of beacons.

6. The optical navigation system of claim 2, wherein said sequenced pattern comprises one beacon of said plurality of beacons providing said electromagnetic radiation at one time.

7. The optical navigation system of claim 2, wherein said sequenced pattern comprises more than one of said plurality of beacons providing said electromagnetic radiation at one time.

8. The optical navigation system of claim 1, wherein said predetermined locations are adjusted by a mechanism based on at least one parameter of said pose.

9. The optical navigation system of claim 1, wherein said on-board centroid sensing device comprises a position sensitive detector selected from the group consisting of semiconductor-type position sensitive detectors, optical waveguide-based position sensitive detectors and organic material position sensitive detectors.

10. The optical navigation system of claim 9, wherein said position sensitive detector is a segmented semiconductor-type position sensitive detector.

11. The optical navigation system of claim 9, wherein said position sensitive detector conforms to a field of view of said optic.

12. The optical navigation system of claim 9, wherein said position sensitive detector is non-planar.

13. The optical navigation system of claim 1, wherein at least one beacon of said plurality of beacons is affixed to a host structure.

14. The optical navigation system of claim 13, wherein said host structure comprises a computing device.

15. The optical navigation system of claim 13, wherein said host structure comprises a communications device.

16. The optical navigation system of claim 13, wherein said host structure comprises a jotting surface.

17. The optical navigation system of claim 1, wherein said plurality of beacons comprise light emitting elements that emit said electromagnetic radiation at an infrared wavelength.

18. The optical navigation system of claim 1, wherein said object comprises a hand-held device.

19. The optical navigation system of claim 18, wherein said hand-held device comprises a jotting implement for cooperating with a jotting surface in said environment.

20. The optical navigation system of claim 19, wherein said plurality of beacons are indexed to said jotting surface.

21. The optical navigation system of claim 18, wherein said hand-held device comprises a hand-held implement for cooperating with a display in said environment.

22. The optical navigation system of claim 21, wherein at least one of said plurality of beacons is indexed to said display.

23. A method for optically determining at least one parameter of a pose of an object in an environment, said method comprising:

a) affixing a plurality of beacons at predetermined locations in said environment for providing an electromagnetic radiation in a sequenced pattern;

b) providing said object with an on-board optic for imaging said electromagnetic radiation onto an on-board centroid sensing device for determining a centroid of an imaged distribution of said electromagnetic radiation;

c) determining said at least one parameter of said pose from said centroid.

24. The method of claim 23, further comprising the step of controlling said sequenced pattern based on said at least one parameter of said pose.

25. The method of claim 23, wherein said at least one parameter of said pose comprises an absolute value of said at least one parameter referenced in said environment.

26. The method of claim 25, wherein said method further comprises determining an absolute position of a point of said object in said environment.

27. The method of claim 25, further comprising producing a user feedback of said absolute value.

28. The method of claim 27, wherein said user feedback comprises a trace.

29. The method of claim 23, further comprising determining a relative motion from said at least one parameter of said pose.

30. The method of claim 29, wherein said relative motion determination comprises an optical flow computation.

31. The method of claim 29, further comprising producing a user feedback of said relative motion.

32. The method of claim 31, wherein said user feedback comprises a visual indicator.