System and Method for Determining an Attitude of a Device Undergoing Dynamic Acceleration

• US 20100097316A1
• Filed: 12/18/2008
• Published: 04/22/2010
• Est. Priority Date: 10/20/2008
• Status: Active Grant

• Current Assignee: Sensor Platforms, Incorporated (Knowles Corporation)
• Original Assignee: Sensor Platforms, Incorporated (Knowles Corporation)
• Inventors: Shaw, Kevin A., Chen, Ian
• Granted Patent: US 8,576,169 B2
• Time in Patent Office: Days
• US Class Current: 345/158
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• 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

A system and a method for determining an attitude of a device undergoing dynamic acceleration is presented. A first attitude measurement is calculated based on a magnetic field measurement received from a magnetometer of the device and a first acceleration measurement received from a first accelerometer of the device. A second attitude measurement is calculated based on the magnetic field measurement received from the magnetometer of the device and a second acceleration measurement received from a second accelerometer of the device. A correction factor is calculated based at least in part on a difference of the first attitude measurement and the second attitude measurement. The correction factor is then applied to the first attitude measurement to produce a corrected attitude measurement for the device.

Claims

1. A method for determining an attitude of a device undergoing dynamic acceleration, comprising:

calculating a first attitude measurement based on a magnetic field measurement received from a magnetometer of the device and a first acceleration measurement received from a first accelerometer of the device;

calculating a second attitude measurement based on the magnetic field measurement received from the magnetometer of the device and a second acceleration measurement received from a second accelerometer of the device;

calculating a correction factor based at least in part on a difference of the first attitude measurement and the second attitude measurement; and

applying the correction factor to the first attitude measurement to produce a dynamic-acceleration-corrected attitude measurement for the device.

2. The method of claim 1, wherein the correction factor includes a scaling factor that is based at least in part on a distance from the first accelerometer and a pivot origin, and a distance from the second accelerometer and the pivot origin.

3. The method of claim 1, including transmitting from the device the corrected attitude measurement to a host system.

4. The method of claim 1, including transmitting from the device signals to a host system indicating that one or more buttons on the device have been pressed.

5. The method of claim 1, including transmitting from the device signals to a host system indicating that a user of the device has performed one or more gestures.

6. The method of claim 1, including transmitting the magnetic field measurement, the first acceleration measurement, and the second acceleration measurement from the device to a host system.

7. The method of claim 1, including receiving at a host system the magnetic field measurement, the first acceleration measurement, and the second acceleration measurement from the device.

8. The method of claim 1, including receiving at a host system signals from the device indicating that one or more buttons of the device have been pressed.

9. The method of claim 1, wherein the first attitude measurement and the second attitude measurement are performed substantially simultaneously.

10. The method of claim 1, including using the corrected attitude measurement to position a cursor displayed on a user interface of a host system.

11. The method of claim 10, including determining a gesture that is being performed by a user of the device.

12. The method of claim 11, wherein the gesture includes a sequence of changes in attitude of the device over a contiguous period of time.

13. The method of claim 11, wherein the gesture includes a combination of a sequence of changes in attitude of the device and one or more buttons being pressed on the device over a contiguous period of time.

14. The method of claim 11,

wherein the gesture corresponds to a command to the host system;

and

wherein determination of the gesture is based on one or more positions of the cursor in the user interface selected from the group consisting of a beginning position of the gesture occurring with the cursor positioned within a first predefined proximity of an object in the user interface, an end of the gesture occurring with the cursor positioned with a second predefined proximity of the object in the user interface, or both the beginning and end of the gesture occurring with the cursor positioned within the first and second proximities of the object, respectively.

15. The method of claim 1, wherein the device includes a multi-dimensional pointing device.

16. The method of claim 1, wherein the first accelerometer is selected from the group consisting of:

a 2-axis accelerometer that measures a magnitude and a direction of an acceleration force in two dimensions; and

a 3-axis accelerometer that measures a magnitude and a direction of an acceleration force in three dimensions.

17. The method of claim 1, wherein the second accelerometer is selected from the group consisting of:

a 2-axis accelerometer that measures a magnitude and a direction of an acceleration force in two dimensions; and

a 3-axis accelerometer that measures a magnitude and a direction of an acceleration force in three dimensions.

18. The method of claim 1, wherein the magnetometer is selected from the group consisting of:

a 2-axis magnetometer that measures a magnitude and a direction of a magnetic field in two dimensions; and

a 3-axis magnetometer that measures a magnitude and a direction of a magnetic field in three dimensions.

19. A multi-dimensional pointing device, comprising

a first accelerometer configured to produce a first multi-dimensional acceleration measurement of the device;

a second accelerometer configured to produce a second multi-dimensional acceleration measurement of the device;

a magnetometer configured to produce a magnetic field measurement; and

one or more processors configured to calculate a dynamic-acceleration-corrected attitude of the device based on the first and the second multi-dimensional accelerometer measurements and the first magnetometer measurement.

20. The multi-dimensional pointing device of claim 19, further comprising:

memory; and

one or more programs stored in the memory for execution by the one or more processors, the one or more programs comprising instructions to;

calculate a first attitude measurement based on a magnetic field measurement received from a magnetometer of the device and a first acceleration measurement received from a first accelerometer of the device;

calculate a second attitude measurement based on the magnetic field measurement received from the magnetometer of the device and a second acceleration measurement received from a second accelerometer of the device;

calculate a correction factor based at least in part on a difference of the first attitude measurement and the second attitude measurement; and

apply the correction factor to the first attitude measurement to produce a corrected attitude measurement for the device.

21. A computer readable storage medium storing one or more programs configured for execution by one or more processors of a device, the one or more programs comprising instructions to:

calculate a first attitude measurement based on a magnetic field measurement received from a magnetometer of the device and a first acceleration measurement received from a first accelerometer of the device;

calculate a second attitude measurement based on the magnetic field measurement received from the magnetometer of the device and a second acceleration measurement received from a second accelerometer of the device;

calculate a correction factor based at least in part on a difference of the first attitude measurement and the second attitude measurement; and

apply the correction factor to the first attitude measurement to produce a corrected attitude measurement for the device.

22. A multi-dimensional pointing device, comprising

a first accelerometer configured to produce a first multi-dimensional acceleration measurement of the device;

a second accelerometer configured to produce a second multi-dimensional acceleration measurement of the device;

a magnetometer configured to produce a magnetic field measurement; and

a transmitter configured to transmit the first multi-dimensional acceleration measurement, the second multi-dimensional acceleration measurement, and the magnetic field measurement to a host system that calculates a dynamic-acceleration-corrected attitude of the device based on the first and the second multi-dimensional accelerometer measurements and the first magnetometer measurement.

23. A system, comprising:

a multi-dimensional pointing device, and a host system coupled by to the multi-dimensional pointing device by a communication channel;

the multi-dimensional pointing device including;

a first accelerometer configured to produce a first multi-dimensional acceleration measurement of the device;

a second accelerometer configured to produce a second multi-dimensional acceleration measurement of the device;

a magnetometer configured to produce a magnetic field measurement;

a transmitter configured to transmit the first multi-dimensional acceleration measurement, the second multi-dimensional acceleration measurement, and the magnetic field measurement to the host system;

the host system, including;

a receiver for receiving the first multi-dimensional acceleration measurement, the second multi-dimensional acceleration measurement, and the magnetic field measurement transmitted by the multi-dimensional pointing device; and

one or more processors that calculate a dynamic-acceleration-corrected attitude of the device based on the first and the second multi-dimensional accelerometer measurements and the first magnetometer measurement.