System and method for using magnetic sensors to track the position of an object

• US 20060061354A1
• Filed: 08/24/2005
• Published: 03/23/2006
• Est. Priority Date: 08/25/2004
• Status: Active Grant

• Current Assignee: Andrea L.M. Baker, Daniel I. Wallance, Wojciech Krajewski
• Original Assignee: Andrea L.M. Baker, Daniel I. Wallance, Wojciech Krajewski
• Inventors: Krajewski, Wojciech, Baker, Andrea L. M., Wallance, Daniel I.
• Granted Patent: US 8,321,173 B2
• Time in Patent Office: Days
• US Class Current: 324/207.150
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G06F 3/0346 with detection of the device orientation or free movement in a 3D space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A method is provided for tracking an object'"'"'s position. One or more semiconductor-based sensors obtain measurements of an energy field associated with the object. A processor applies an algorithm to the measurements to generate one or more values representing a position of the object in a coordinate system. The energy field may comprise a magnetic field, for example. The object may comprise a magnet, for example.

Claims

1. A method for tracking an object'"'"'s position, comprising:

measuring an energy field associated with an object by one or more semiconductor-based sensors to obtain one or more measurements; and

applying an algorithm to the one or more measurements to generate one or more values representing a position of the object in a coordinate system.

2. The method of claim 1, comprising:

measuring a magnetic field associated with an object by one or more semiconductor-based sensors to obtain one or more measurements.

3. The method of claim 1, comprising:

measuring an electromagnetic field associated with an object by one or more semiconductor-based sensors to obtain one or more measurements.

4. The method of claim 1, comprising:

measuring an energy field associated with an object by nine semiconductor-based sensors to obtain one or more measurements.

5. The method of claim 1, comprising:

measuring an energy field associated with an object by three semiconductor-based sensors to obtain one or more measurements, the three sensors being aligned in a mutually orthogonal configuration.

6. The method of claim 1, wherein the object comprises a magnet.

7. The method of claim 1, wherein the object comprises an LC circuit.

8. The method of claim 1, wherein the algorithm comprises:

examining a look-up table comprising at least one set of one or more coordinates representing a location and a corresponding set of one or more values representing components of an energy field.

9. The method of claim 8, wherein the look-up table comprises at least one record holding a set of one or more of the coordinates representing a location and a set of one or more of the values representing components of an energy field,

the method further comprising:

identifying a record holding a set of values at least substantially matching the one or more measurements; and

determining the position of the object to be equal to the set of coordinates stored in the identified record.

10. The method of claim 1, comprising:

applying a best-fit equation to the one or more measurements to generate one or more values representing a position of the object in a coordinate system.

11. The method of claim 1, comprising:

measuring a passively generated energy field.

12. The method of claim 1, comprising:

wirelessly measuring the energy field.

13. The method of claim 11 wherein the coordinate system comprises at least one dimension.

14. The method of claim 13, wherein the coordinate system comprises at least two dimensions.

15. The method of claim 14, wherein the coordinate system comprises at least three dimensions.

16. A position tracking system, comprising:

at least one object configured to generate an energy field;

one or more semiconductor-based sensors configured to;

obtain one or more measurements of the energy field; and

a processor programmed to;

apply an algorithm to the one or more measurements to generate one or more values representing a position of the object in a coordinate system.

17. The system of claim 16, wherein:

the object is configured to generate a magnetic field.

18. The system of claim 17, wherein the object comprises a magnet.

19. The system of claim 16, wherein:

the object is configured to generate an electromagnetic field.

20. The system of claim 16, wherein the one or more semiconductor-based sensors comprise one or more magnetic sensors.

21. The system of claim 16, comprising nine semiconductor-based sensors.

22. The system of claim 16, comprising three semiconductor-based sensors.

23. The system of claim 16, wherein the object comprises an LC circuit.

24. The system of claim 16, further comprising:

storage for storing a look-up table comprising at least one set of one or more coordinates representing a location and a corresponding set of one or more values representing components of an energy field.

25. The system of claim 24, wherein the processor is further programmed to:

examine the look-up table;

identify a record holding a set of values at least substantially matching the one or more measurements; and

determine the position of the object to be equal to the set of coordinates stored in the identified record.

26. The system of claim 16, wherein the processor is programmed to:

apply a best-fit equation to the one or more measurements to generate one or more values representing a position of the object in a coordinate system.

27. The system of claim 16, wherein the object is configured to generate the energy field passively.

28. The system of claim 16, wherein the one or more semiconductor-based sensors are configured to obtain the one or more measurements of the energy field wirelessly.

29. The system of claim 16, wherein the processor comprises software.

30. The system of claim 29, wherein the processor comprises a multithreaded program architecture.

31. The system of claim 30, wherein the coordinate system comprises at least one dimension.

32. The system of claim 31, wherein the coordinate system comprises at least two dimensions.

33. The system of claim 32, wherein the coordinate system comprises at least three dimensions.

34. The system of claim 16, wherein the coordinate system defines multiple positions in a tracking volume defined, at least in part, by the locations of the one or more sensors.

35. The system of claim 16, wherein the object comprises a position indicator unit of a computer mouse device.

36. The system of claim 35, wherein the object comprises a medical diagnostic sensor capsule.

37. The system of claim 16, wherein the object comprises a cardiopulmonary status indicator.

38. The system of claim 16, wherein the computer mouse device is in the shape of a ring.

39. A position tracking system, comprising:

an object that generates an energy field;

a sensing device comprising;

at least a first platform comprising at least one magnetic sensor to detect a first component of the energy field, the first platform disposed in a first plane; and

a processor programmed to;

determine a location of the object based on measurements obtained by at least one of the magnetic sensors located on the first platform.

40. The position tracking system of claim 39, comprising three magnetic sensors positioned in a mutually orthogonal configuration.

41. The position tracking system of claim 39, further comprising:

a second platform comprising at least one magnetic sensor to detect a second component of the energy field, the second platform disposed in a second plane substantially orthogonal to the first plane.

42. The position tracking system of claim 41, further comprising:

a third platform comprising at least one magnetic sensor to detect a third component of the energy field, the third platform disposed in a third plane substantially orthogonal to the first and second planes.

43. The position tracking system of claim 42, wherein the first, second and third platforms are positioned in a mutually orthogonal configuration to define a tracking volume.