Optical navigation apparatus using fixed beacons and a centroid sensing device

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (Prior Art) is a three-dimensional diagram illustrating a prior art method of using position sensitive devices to track moving objects.

FIG. 2 is a three-dimensional diagram illustrating an optical navigation system according to the invention.

FIG. 3 is a diagram illustrating the Euler rotation convention employed in the navigation system of the invention.

FIG. 4A is a graph illustrating the intensity of a typical ambient emission spectrum.

FIG. 4B is a graph illustrating a transmittance of an infrared filter employed in the embodiment of FIG. 2.

FIG. 5 is a diagram with a top plan view of the surface of a centroid sensing device in the form of a position sensitive detector (PSD).

FIG. 6 is a diagram of an exemplary motion capture program employing absolute and relative navigation algorithms.

FIG. 7A is an isometric view of a PSD for optical navigation in accordance with the invention.

FIG. 7B is a cross-sectional side view of another centroid sensing device for optical navigation in accordance with the invention.

FIG. 7C is an isometric view of still another PSD for optical navigation in accordance with the invention.

FIG. 8 is a top plan view of a position sensing device with circular symmetry for use in optical navigation in accordance with the invention.

FIG. 9 is a simplified schematic view of a navigation system employed in a surface constrained application such as jotting.

FIG. 10 is a diagram with a top plan view of the position sensing device (PSD) used by the navigation system of FIG. 9.

FIG. 11 is a three-dimensional diagram of a navigation system for a hand-held object used with a host computer and standard communications devices.

FIG. 12 is an three-dimensional diagram of a navigation system for hand-held objects with relative motion interpolation and biometric capabilities.

FIG. 13 is a three-dimensional diagram of a navigation system for a clipboard host structure.

FIG. 14 is a three-dimensional diagram of a navigation system employing on-board illumination and retroreflecting beacons.

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.