MAGNETIC SYNCHRONIZATION FOR A POSITIONING SYSTEM

• US 20140293748A1
• Filed: 03/28/2014
• Published: 10/02/2014
• Est. Priority Date: 03/29/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Altman, Nathan, Agassy, Meir, Kedem, Noam Z., Winebrand, Vadim, Rotem, Gal, Lerner, Arye
• Granted Patent: US 9,897,682 B2
• Time in Patent Office: Days
• US Class Current: 367/127
• CPC Class Codes: G01S 3/8083 determining direction of source
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/0433 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

Abstract

A synchronization system for an acoustic signal-based positioning system is provided that generates a magnetic field as a synchronization signal. The magnetic synchronization signal is transmitted by a transmitter of the positioning system and received by the receiver of the positioning system. The receiver may include a magnetic synchronization signal receiver that may receive the magnetic synchronization signal on a same acoustic channel as an acoustic positioning signal. Moreover, the magnetic synchronization signal receiver may be a component already present in the receiver and capable of receiving a magnetic synchronization signal.

Claims

1. A positioning system, comprising:

a transmitter, the transmitter comprising;

an acoustic signal transmitter configured to transmit a modulated acoustic signal; and

a magnetic synchronization signal transmitter configured to transmit a modulated magnetic synchronization signal;

a receiver, the receiver comprising;

an acoustic signal receiver configured to receive the transmitted modulated acoustic signal;

a magnetic synchronization signal receiver configured to receive the transmitted modulated magnetic synchronization signal; and

a processing component configured to receive the modulated acoustic signal from the acoustic signal receiver and the modulated magnetic synchronization signal form the magnetic synchronization signal receiver on a same time domain and using similar circuits for acoustic and magnetic signals to determine a position of the transmitter based on the received modulated synchronization signal and a determined time delay of the received modulated acoustic signal.

2. The positioning system of claim 1, wherein the transmitted modulated acoustic signal comprises a modulated continuous ultrasonic signal.

3. The positioning system of claim 1, wherein the magnetic synchronization signal transmitter comprises a wiring wrapped around a core.

4. The positioning system of claim 3, wherein the core comprises a ferrite core.

5. The positioning system of claim 4, wherein the ferrite core comprises flanges at either end of the ferrite core.

6. The positioning system of claim 1, wherein the magnetic synchronization signal transmitter comprises a hollow cylinder.

7. The positioning system of claim 1, wherein the magnetic synchronization signal receiver comprises a coil.

8. The positioning system of claim 7, wherein the coil is used for assistive listening features.

9. The positioning system of claim 7, wherein the coil is a wireless charging coil.

10. The positioning system of claim 7, wherein the coil is a near-field communications (NFC) coil.

11. The positioning system of claim 1, wherein the transmitter comprises a digital pen.

12. The positioning system of claim 1, wherein the receiver comprises a computing device.

13. The positioning system of claim 1, wherein the processing component is configured to determine the time delay of the received modulated acoustic signal based on the received modulated magnetic synchronization signal.

14. The position system of claim 13, wherein the transmitter comprises a first clock and wherein the receiver comprises a second clock, wherein the processing component is configured to synchronize the second clock with the first clock based on the received modulated magnetic synchronization signal, and wherein the processing component is configured to determine the time delay of the received modulated acoustic signal based on the synchronized second clock.

15. A receiving device for an acoustic signal-based positioning system, comprising:

an acoustic signal receiver configured to receive a modulated acoustic signal;

a magnetic synchronization signal receiver configured to receive a modulated magnetic synchronization signal; and

a processing component configured to receive the modulated acoustic signal from the acoustic signal receiver and the modulated magnetic synchronization signal from the magnetic synchronization signal receiver on a single path and using similar circuits for acoustic and magnetic signals to determine a position of an object emitting the modulated acoustic signal and the modulated magnetic synchronization signal based on the received modulated synchronization signal and a determined time delay of the received modulated acoustic signal.

16. The receiving device of claim 15, wherein the modulated acoustic signal comprises a modulated continuous ultrasonic signal.

17. The receiving device of claim 15, wherein the magnetic synchronization signal receiver comprises a coil.

18. The receiving device of claim 17, wherein the coil is used for assistive listening features.

19. The receiving device of claim 17, wherein the coil is a wireless charging coil.

20. The receiving device of claim 17, wherein the coil is a near-field communications (NFC) coil.

21. The receiving device of claim 15, wherein the modulated acoustic signal and the modulated magnetic synchronization signal have a same modulation.

22. The receiving device of claim 15, wherein the processing component is configured to determine the time delay of the received modulated acoustic signal based on the received magnetic synchronization signal.

23. The receiving device of claim 22, wherein the receiver further comprises a clock, the processing component being further configured to synchronize the clock based on the received magnetic synchronization signal, and wherein the processing component is further configured to determine the time delay of the received modulated acoustic signal based on the synchronized clock.

24. A method for determining a position of an object, comprising:

receiving, by a detector arrangement, at least one modulated ultrasonic waveform and a modulated magnetic synchronization signal emitted by the object, wherein receiving the at least one modulated ultrasonic waveform comprises receiving at least a first version of the at least one modulated ultrasonic waveform at a first acoustic sensor of the detector arrangement and a second version of the at least one modulated ultrasonic waveform at a second acoustic sensor of the detector arrangement;

decoding, by a processing unit, the received versions of the modulated ultrasonic waveform and the received modulated magnetic synchronization signal, wherein the received versions of the modulated ultrasonic waveform and the received modulated magnetic synchronization signal are received by the processing unit on a same path;

measuring, by the processing unit, a time delay between each of the decoded versions of the modulated ultrasonic waveform and the decoded modulated magnetic synchronization signal;

converting, by the processing unit, the measured time delays to at least a first distance and a second distance; and

determining, by the processing unit, the position of the object based on triangulating the first distance and the second distance.

25. The method of claim 24, further comprising synchronizing a first clock associated with the object with a second clock associated with the processing unit using the received modulated magnetic synchronization signal.

26. The method of claim 25, wherein synchronizing comprises compensating for a clock drift of the second clock and the first clock.

27. A system for determining a position of an object, comprising:

means for receiving at least one modulated ultrasonic waveform and a modulated magnetic synchronization signal emitted by the object, wherein the means for receiving is configured to receive at least a first version of the at least one modulated ultrasonic waveform at a first sensing means of the means for receiving and a second version of the at least one modulated ultrasonic waveform at a second sensing means of the means for receiving;

means for decoding the received versions of the modulated ultrasonic waveform and the received modulated magnetic synchronization signal, wherein the received versions of the modulated ultrasonic waveform and the received modulated magnetic synchronization signal are received by the processing unit on a same path;

means for measuring a time delay between each of the decoded versions of the modulated ultrasonic waveform and the decoded modulated magnetic synchronization signal;

means for converting the measured time delays to at least a first distance and a second distance; and

means for determining the position of the object based on triangulating the first distance and the second distance.

28. The system of claim 27, further comprising means for synchronizing a first clock associated with the object with a second clock associated with the processing unit using the received modulated magnetic synchronization signal.

29. The system of claim 28, wherein the means for synchronizing is configured to compensate for a clock drift of the second clock and the first clock.

measuring a time delay between each of the decoded versions of the modulated ultrasonic waveform and the decoded modulated magnetic synchronization signal;

converting the measured time delays to at least a first distance and a second distance; and

determining the position of the object based on triangulating the first distance and the second distance.