Determining location using time difference of arrival

Patent metadata

Field	Value
Publication number	US-10591580-B2
Application number	US-201415513758-A
Country	US
Kind code	B2
Filing date	Sep 23, 2014
Priority date	Sep 23, 2014
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

Example implementations relate to determining a location using time difference of arrival (TDOA). For example, a computing device may include a first sensor to receive a signal at a first time, where the signal is generated by a user contact at a particular location on a keyboard associated with the computing device. The computing device also includes a second sensor to receive the signal at a second time and a third sensor to receive the signal at a third time. The computing device may also include a processor. The processor may calculate a set of TDOAs associated with the first time, the second time, and the third time. The processor may determine the particular location of the user contact using a triangulation based on the set of TDOAs and may identify a character on the keyboard, where the character is associated with the particular location.

First claim

What is claimed is:

1. A computing device comprising:
a wireless communication device, wherein the wireless communication device is communicatively coupled to a processor, and the wireless communication device receives a calibration signal from a physical keyboard;
a virtual keyboard superimposed on a surface of the physical keyboard;
a first sensor to receive a signal at a first time, the signal generated by a user contact of the physical keyboard at a particular location within the virtual keyboard;
a second sensor to receive the signal at a second time;
a third sensor to receive the signal at a third time; and
the processor to:
calculate a set of time differences of arrival (TDOAs) associated with the first time, the second time, and the third time;
determine the particular location within the virtual keyboard of the user contact of the physical keyboard using a triangulation based on the set of TDOAs based on the calibration signal;
identify a character on the virtual keyboard, the character being associated with the particular location of the physical keyboard; and
determine an angle of orientation of the physical keyboard with respect to the computing device based on the particular location of the physical keyboard of the identified character on the virtual keyboard.

2. The computing device of claim 1 , wherein the first sensor, the second sensor, and the third sensor are each a microphone or an accelerometer.

3. The computing device of claim 1 , wherein the processor is
further to access additional information relating to at least one of a keyboard layout of the physical keyboard and machine-learned information, the particular location within the virtual keyboard being determined using the triangulation and the additional information.

4. The computing device of claim 1 , wherein power to the physical keyboard is turned on only during the calibration.

5. A method comprising:
receiving a calibration signal by a wireless communication device of a computing device;
detecting a signal by a first sensor of the computing device at a first time, a second sensor of the computing device at a second time, and a third sensor of the computing device at a third time, the signal generated by a user contact of a physical keyboard at a particular location within a virtual keyboard associated with the computing device;
generating, by the computing device, a set of time differences of arrival (TDOAs) associated with the first time, the second time, and the third time;
triangulating, by the computing device, the particular location within the virtual keyboard of the user contact of the physical keyboard using the set of TDOAs and the calibration signal;
determining a character on the virtual keyboard using a cluster map, the character being associated with the particular location of the virtual keyboard; and
determining, by the computing device, an angle of orientation of the physical keyboard with respect to the computing device based on the particular location within the virtual keyboard of the determined character on the virtual keyboard.

6. The method of claim 5 , wherein the first sensor, the second sensor, and the third sensor are each a microphone or an accelerometer.

7. The method of claim 5 , further comprising:
accessing additional information relating to at least one of a keyboard layout of the physical keyboard and machine-learned information, the particular location within the virtual keyboard being determined using the additional information.

8. A computing device comprising:
a wireless communication device, wherein the wireless communication device is communicatively coupled to a processor, and the wireless communication device receives a calibration signal from a physical keyboard;
a first sensor to receive a signal at a first time, the signal generated by a user contact of the physical keyboard at a particular location within a virtual keyboard, wherein the virtual keyboard is superimposed on a surface the physical keyboard;
a second sensor to receive the signal at a second time; and
the processor to:
calculate a time difference of arrival (TDOA) associated with the first time and the second time;
access additional information relating to the physical keyboard with respect to the computing device;
determine the particular location within the virtual keyboard of the user contact of the physical keyboard using the TDOA, the additional information and the calibration signal;
identify a character on the virtual keyboard using a cluster map, the character being associated with the particular location within the virtual keyboard; and
determine an angle of orientation of the physical keyboard with respect to the computing device based on the particular location within the virtual keyboard of the identified character.

9. The computing device of claim 8 , wherein the first sensor and the second sensor are each a microphone or an accelerometer.

10. The computing device of claim 8 , wherein the additional information includes at least one of a keyboard layout of the physical keyboard, information associated with signal signatures of the signal received at the first sensor and the second sensor, and machine-learned information.

11. The computing device of claim 8 , wherein the cluster map is generated based on the user contact of the physical keyboard with the particular location within the virtual keyboard associated with each cluster, and machine-learning is used to identify whether a keystroke is associated with a particular cluster.

12. The computing device of claim 8 , wherein the additional information used is a layout of the physical keyboard to determine the physical keyboard orientation from two calculated TDOAs.

13. The computing device of claim 8 , wherein the calculated TDOA is determined using a least-squares technique.

Assignees

• Hewlett Packard Development Co

Inventors

• Lee Bowon
• Sen Souvik

Classifications

• G01S5/26 Primary

  Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements (G01S5/28 takes precedence) · CPC title

• G06F3/04886

  by partitioning the display area of the touch-screen or the surface of the digitising tablet into independently controllable areas, e.g. virtual keyboards or menus · CPC title

• G06F3/02

  Input arrangements using manually operated switches, e.g. using keyboards or dials · CPC title

• G06F3/0433

  in which the acoustic waves are either generated by a movable member and propagated within a surface layer or propagated within a surface layer and captured by a movable member · CPC title

• G01S5/28

  by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial · CPC title