Six-degree-of-freedom, integrated-coil AC magnetic tracker

• US 20060255795A1
• Filed: 05/10/2006
• Published: 11/16/2006
• Est. Priority Date: 05/13/2005
• Status: Abandoned Application

• Current Assignee: Alken Inc.
• Original Assignee: Alken Inc.
• Inventors: Dickinson, Donald M., Rodgers, Allan G., Higgins, Robert F.
• Application Number:
  US11/431,470
• Publication Number:
  US 20060255795A1
• Time in Patent Office: Days
• US Class Current: 324/207.170
• 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

Abstract

The 3-axis field source coils and 3-axis sensor coils derived from off-the-shelf suppliers in a magnetic tracker are integrated with driving and sensing circuitry to provide a complete six-degree-of-freedom tracker in only two modules: a sensor module and a source module plus being able also to track with at least a second sensor of identical design. One or both of the basic tracker modules may be mounted on respective single printed-circuit boards, and the source module may take advantage of digital wave generation and tuned coil drivers for reduced hardware. One or both of the coil sets may be non-concentric, and the output for providing P&O updates to a host computer may take advantage of a connector that receives electrical power from the host computer, such as a USB/USB-2 connector. To further reduce system cost, the circuitry used to amplify the signals received by the sensor coils may be multiplexed under control of the processor on the source board.

Claims

1. An AC magnetic tracking system, comprising:

a sensor module including;

at least one set of sensor coils,

circuitry to amplify signals received by the sensor coils;

a source module including;

a set of source coils and coil drivers,

an input for receiving the amplified signals from the sensor module,

a processor for computing the position and orientation (P&

O) of the sensor module based upon the signals received, and

an output for providing P&

O updates to a host computer; and

a cable interconnecting the two modules for delivery of the amplified sensor signals to the processor for the P&

O computations.

2. The AC magnetic tracking system of claim 1, wherein the cable is interfaced to one or both of the modules through a connector.

3. The AC magnetic tracking system of claim 1, wherein the source module uses digital wave generation and tuned coil drivers.

4. The AC magnetic tracking system of claim 1, wherein one or both of the modules are each mounted on a single printed-circuit board.

5. The AC magnetic tracking system of claim 1, wherein one or both of the coil sets are non-concentric.

6. The AC magnetic tracking system of claim 1, wherein the output for providing P&

O updates to a host computer uses a connection that receives electrical power from the host computer.

7. The AC magnetic tracking system of claim 1, wherein the circuitry to amplify signals received by the sensor coils is multiplexed on a per-coil basis under control of the processor in the source module.

8. An AC magnetic tracking system, comprising:

a sensor module including a set of sensor coils,

a source module including;

a set of source coils and coil drivers,

an input for receiving signals from the sensor module,

a processor for computing the position and orientation (P&

O) of the sensor module based upon the signals received, and

an output for providing P&

O updates to a host computer; and

wherein the source module uses digital wave generation and tuned coil drivers.

9. The AC magnetic tracking system of claim 8, wherein one or both of the modules are each mounted on a single printed-circuit board.

10. The AC magnetic tracking system of claim 8, wherein one or both of the coil sets are non-concentric.

11. The AC magnetic tracking system of claim 8, wherein the circuitry to amplify signals received by the sensor coils is multiplexed on a per-coil basis under control of the processor in the source module.

12. An AC magnetic tracking system, comprising:

a sensor module including a set of sensor coils,

a source module including;

a set of source coils and coil drivers,

an input for receiving signals from the sensor module,

a processor for computing the position and orientation (P&

O) of the sensor module based upon the signals received, and

an output for providing P&

O updates to a host computer; and

wherein the output uses a connector that receives electrical power from the host computer.

13. The AC magnetic tracking system of claim 12, wherein the cable is interfaced to one or both of the modules through a connector.

14. The AC magnetic tracking system of claim 12, wherein the source module uses digital wave generation and tuned coil drivers.

15. The AC magnetic tracking system of claim 12, wherein one or both of the modules are each mounted on a single printed-circuit board.

16. The AC magnetic tracking system of claim 12, wherein one or both of the coil sets are non-concentric.

17. The AC magnetic tracking system of claim 12, wherein the circuitry to amplify signals received by the sensor coils is multiplexed on a per-coil basis under control of the processor in the source module.

18. The AC magnetic tracking system of claim 12, wherein the processor is operative process at least two sensor outputs and control sensor preamplifiers using the same multiplexing signals that would be sent to a single sensor.