Detecting positions of magnetic flux sensors having particular locations on a device relative to a magnetic field generator located at a predetermined position on the device

Patent metadata

Field	Value
Publication number	US-11029757-B1
Application number	US-201916729929-A
Country	US
Kind code	B1
Filing date	Dec 30, 2019
Priority date	Sep 24, 2015
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A wearable device (such as a glove or other control adapted to be worn on a portion of a body) includes multiple magnetic field generators at various locations on the wearable device and a magnetic flux sensor at a predetermined position relative to the wearable device. A position determines spatial positions of locations of the wearable device based on magnetic fields generated by various magnetic field generators and detected by the magnetic flux sensor. In some embodiments, the magnetic field generators have known positions relative to each other. Additionally, each magnetic field generator may generate a magnetic field in response to an input signal having a particular attribute, allowing the magnetic flux sensor to identify magnetic fields generated by different magnetic field generators.

First claim

What is claimed is:

1. A device comprising:
a magnetic field generator located at a predetermined position on the device, the magnetic field generator configured to generate a modulated magnetic field that is fixed in relation to the device;
a plurality of magnetic flux sensors located at particular locations on the device, the particular locations on different fingers of a user of the device, each magnetic flux sensor configured to: (1) generate a demodulated signal based on detecting the modulated magnetic field at the particular location, (2) detect a strength and a direction of the demodulated signal, and (3) generate an output signal based on the detected strength and the detected direction of the demodulated signal
one or more inertial measurement units (IMUs), each IMU being configured to generate a signal for an angular orientation of a particular magnetic flux sensor of the plurality of magnetic flux sensors, the particular magnetic flux sensor located on a finger of the user; and
a position analyzer coupled to each of the plurality of magnetic flux sensors, the position analyzer configured to determine spatial vectors representing a position of each magnetic flux sensor relative to the magnetic field generator, wherein:
the position of a magnetic flux sensor relative to the magnetic field generator is based on demodulating an output signal generated by the magnetic flux sensor, and
the position analyzer is configured to determine further positional information for at least some of the plurality of magnetic flux sensors located on the fingers of the user based on the signal generated by the one or more IMUS.

2. The device of claim 1 , wherein the magnetic field generator comprises one or more electromagnets.

3. The device of claim 2 , wherein each magnetic flux sensor includes a measurement circuit configured to extract a magnetic field having a certain frequency.

4. The device of claim 3 , wherein different magnetic flux sensors include measurement circuits configured to extract magnetic fields having different frequencies.

5. The device of claim 1 , wherein the magnetic field generator comprises a plurality of permanent magnets having known relative spatial positions and known relative orientations to each other.

6. The device of claim 1 , wherein the magnetic field generator comprises a plurality of programmable magnets.

7. The device of claim 1 , wherein the spatial vectors determined by the position analyzer correspond to spatial positions and orientations of fingers of the user where each magnetic flux sensor is located.

8. The device of claim 1 , wherein the device comprises a glove.

9. A device comprising:
a magnetic field generator located at a predetermined position on the device, the magnetic field generator configured to generate a modulated magnetic field that is fixed in relation to the device;
a plurality of magnetic flux sensors located at particular locations on the device, the particular locations on a body of a user of the device, each magnetic flux sensor configured to: (1) generate a demodulated signal based on detecting the modulated magnetic field at the particular location; (2) detect a strength and a direction of the demodulated signals and (3) generate an output signal based on the detected strength and the detected direction of the demodulated signals;
one or more inertial measurement units (IMUs), each IMU being configured to generate a signal for an angular orientation of a particular magnetic flux sensor of the plurality of magnetic flux sensors, the particular magnetic flux sensor located on a particular location on the body of the user; and
a position analyzer coupled to each of the plurality of sensors, the position analyzer configured to determine spatial vectors representing a position of each magnetic flux sensor relative to the magnetic field generator, wherein:
the position of a magnetic flux sensor relative to the magnetic field generator is based on demodulating an output signal generated by the magnetic flux sensor, and
the position analyzer is configured to determine further positional information for at least some of the plurality of magnetic flux sensors located on the particular location on the body of the user based on the signal generated by the one or more IMUs.

10. The device of claim 9 , wherein the magnetic field generator comprises one or more electromagnets.

11. The device of claim 10 , wherein each magnetic flux sensor includes a measurement circuit configured to extract a magnetic field having a certain frequency.

12. The device of claim 11 , wherein different magnetic flux sensors include measurement circuits configured to extract magnetic fields having different frequencies.

13. The device of claim 9 , wherein the magnetic field generator comprises a plurality of permanent magnets having known relative spatial positions and known relative orientations to each other.

14. The device of claim 9 , wherein the magnetic field generator comprises a plurality of programmable magnets.

15. The device of claim 9 , wherein the spatial vectors determined by the position analyzer correspond to spatial positions and orientations of the particular locations on the body of the user where each magnetic flux sensor is located.

16. A method comprising:
generating a modulated magnetic field that is fixed in relation to a device from a magnetic field generator located at a predetermined position on the device;
detecting, by each of a plurality of magnetic flux sensors located at particular locations on the device that correspond to portions of a body of a user of the device located at a predetermined position relative to the device, the modulated magnetic field;
generating, by each of the magnetic flux sensors located at particular locations on the device that correspond to portions of a body of a user of the device located at a predetermined position relative to the device, a demodulated signal based on the detected modulated field by each of the magnetic flux sensors;
detecting, by each of the plurality of magnetic flux sensors, a strength and a direction of the demodulated signals;
generating an output signal by each of the plurality of magnetic flux sensors based on the detected strength and the detected direction of the demodulated signals at each of the magnetic flux sensors;
generating, by each of one or more inertial measurement units (IMUs), a signal for an angular orientation of a particular magnetic flux sensor of the plurality of magnetic flux sensors, the particular magnetic flux sensor located on a particular location on the body of the user;
determining spatial vectors representing a position of each magnetic flux sensor relative to the magnetic field generator based on demodulating an output signal generated by the magnetic flux sensor; and
determining further positional information for at least some of the plurality of magnetic flux Censor located on the particular locations on the body of the user based on the generated signal by the one or more IMUS.

17. The method of claim 16 , wherein the magnetic field generator comprises one or more electromagnets.

18. The method of claim 17 , wherein each magnetic flux sensor includes a measurement circuit configured to extract a magnetic field having a certain frequency.

19. The method of claim 18 , wherein different magnetic flux sensors include measurement circuits configured to extract magnetic fields having different frequencies.

20. The method of claim 16 , wherein the magnetic field generator c

Assignees

• Facebook Tech Llc

Inventors

• Chen Ke-Yu
• Keller Sean Jason
• Perek David R
• Trutna Tristan Thomas
• Cleary Iii Bruce A

Classifications

• G06F3/014 Primary

  Hand-worn input/output arrangements, e.g. data gloves · CPC title

• G06F3/0346

  with detection of the device orientation or free movement in a three-dimensional [3D] space, e.g. 3D mice, 6-DOF [six degrees of freedom] pointers using gyroscopes, accelerometers or tilt-sensors · CPC title

• G01B7/004

  for measuring coordinates of points · CPC title

• G06F3/017

  Gesture based interaction, e.g. based on a set of recognized hand gestures (interaction based on gestures traced on a digitiser G06F3/04883) · CPC title