System and method of providing communications in a wireless power transfer system

• US 10,277,279 B2
• Filed: 06/14/2016
• Issued: 04/30/2019
• Est. Priority Date: 02/07/2011
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Inventors: Norconk, Matthew J., Schwannecke, Joshua K., Moore, Colin J., Taylor, Joshua B., Kuyvenhoven, Neil W., Liff, Dale R., Amistadi, Jason L., Gruich, Robert D., Kelley, Arthur, Armstrong, Kenneth C.
• Primary Examiner(s): Koeth, Michelle M
• Application Number:
  US15/181,947
• Publication Number:
  US 20160294445A1
• Time in Patent Office: 1,050 Days
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H03K 7/10 Combined modulation, e.g. rate modulation and amplitude modulation
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A communication system that uses keyed modulation to encode fixed frequency communications on a variable frequency power transmission signal in which a single communication bit is represented by a plurality of modulations. To provide a fixed communication rate, the number of modulations associated with each bit is dynamic varying as a function of the ratio of the communication frequency to the carrier signal frequency. In one embodiment, the present invention provides dynamic phase-shift-keyed modulation in which communications are generated by toggling a load at a rate that is a fraction of the power transfer frequency. In another embodiment, the present invention provides communication by toggling a load in the communication transmitter at a rate that is phase locked and at a harmonic of the power transfer frequency. In yet another embodiment, the present invention provides frequency-shift-keyed modulation, including, for example, modulation at one of two different frequencies.

Claims

1. A method of communicating data between a remote device and an inductive power supply using keyed modulation, said method comprising:

receiving inductive power via a variable frequency power transmission signal from the inductive power supply;

encoding a data stream of bits into a communication signal;

generating a modulation signal based on the communication signal and one or more modulation clock signals, wherein each bit of the data stream is represented by a plurality of modulations in the modulation signal;

modulating the variable frequency power transmission signal according to the modulation signal by toggling a load of a communication transmitter; and

varying at least one of the one or more modulation clock signals based on variations in a frequency of the variable frequency power transmission signal, wherein the variable frequency power transmission signal is capable of varying in response to a change in at least one operating parameter of the inductive power supply, whereby the at least one of the one or more modulation clock signals is varied based on the change in the at least one operating parameter of the inductive power supply, and wherein the data stream from the variable frequency power transmission signal is decoded by time slicing the variable frequency power transmission signal and identifying DC offsets among time slices.

2. The method as claimed in claim 1 wherein said modulating includes amplitude modulating the variable frequency power transmission signal according to the modulation signal by toggling the load of the communication transmitter.

3. The method as claimed in claim 1 wherein a number of amplitude modulations associated with each bit of the data stream varies based on changes in a modulation frequency of the one or more modulation clock signals.

4. The method as claimed in claim 1 wherein the communication transmitter is configured to modulate the load, and wherein said modulating includes toggling the load in the communication transmitter based on a modulation clock frequency that is a fraction of the variable frequency power transmission signal.

5. The method as claimed in claim 4 wherein the modulation clock frequency is one-half the variable frequency power transmission signal.

6. The method as claimed in claim 4 wherein said modulating includes toggling the load to increase a magnitude of every other waveform of the variable frequency power transmission signal.

7. The method as claimed in claim 6 wherein said modulating includes toggling the load on every even waveform or every odd waveform.

8. The method as claimed in claim 4 wherein said modulating includes toggling the load to increase a magnitude of the peak or the trough of every other waveform of the variable frequency power transmission signal.

9. The method as claimed in claim 1 wherein generating the modulation signal includes exclusive OR-ing (a) one or more of the modulation clock signals that is operating at an even integer fraction of the variable frequency power transmission signal and (b) the communication signal.

10. The method as claimed in claim 1, wherein the DC offsets between the time slices are compared.

11. The method as claimed in claim 1 wherein the one or more modulation clock signals are phase locked at a harmonic frequency of the variable frequency power transmission signal.

12. The method as claimed in claim 11 wherein the harmonic frequency is four times the variable frequency power transmission signal.

13. The method as claimed in claim 11 wherein said modulating includes:

producing a first modulation signal formed by exclusive OR-ing (a) one of the modulation clock signals operating at the harmonic frequency and (b) the communication signal;

producing a second modulation signal formed by inverting the exclusive OR of (a) the one modulation clock signal operating at the harmonic frequency and (b) the communication signal;

toggling the load according to the first modulation signal during a positive half of the variable frequency power transmission signal; and

toggling the load according to the second modulation signal during a negative half of the variable frequency power transmission signal.

14. The method as claimed in claim 1 wherein the communication transmitter is configured to modulate the load based on the modulation clock signals operating at different frequencies.

15. A remote device for receiving power from an inductive power supply and for communicating data to the inductive power supply, said remote device comprising:

a power receiver adapted to receive a variable frequency power transmission signal;

a controller adapted to encode a data stream of bits into a modulation signal based on one or more modulation clock signals, each bit of the data stream being represented by a plurality of modulations in the modulation signal, wherein at least one of the modulation clock signals varies based on variations in a frequency of the variable frequency power transmission signal, wherein the variable frequency power transmission signal is capable of varying in response to a change in at least one operating parameter of the inductive power supply, wherein the at least one of the one or more modulation clock signals is varied based on the change in the at least one operating parameter of the inductive power supply; and

a communication transmitter adapted to selectively toggle a load on the variable frequency power transmission signal according to the modulation signal, wherein the data stream from the variable frequency power transmission signal is decodable by time slicing the variable frequency power transmission signal and identifying DC offsets among time slices.

16. The remote device as claimed in claim 15 wherein a number of modulations in the modulation signal that are associated with each bit of the data stream varies based on changes in the one or more modulation clock signals.

17. The remote device as claimed in claim 15 wherein the communication transmitter is configured to modulate the load, and wherein said load in the communication transmitter is modulated based on a modulation clock frequency that is a fraction of the frequency of the variable frequency power transmission signal.

18. The remote device as claimed in claim 17 wherein the modulation clock frequency is one-half the variable frequency power transmission signal.

19. The remote device as claimed in claim 17 wherein the load is toggled to increase a magnitude of every other waveform of the variable frequency power transmission signal.

20. The remote device as claimed in claim 19 wherein the load is toggled on every even waveform or every odd waveform.

21. The remote device as claimed in claim 17 wherein the load is toggled to increase a magnitude of the peak or the trough of every other waveform of the variable frequency power transmission signal.

22. A system for transferring power to a remote device from an inductive power supply and for communicating data between the remote device and the inductive power supply using keyed modulation, said system comprising:

a power receiver adapted to receive a variable frequency power transmission signal;

a controller for encoding a data stream of bits in to a modulation signal based on one or more modulation clock signals, each bit of the data stream being represented by a plurality of modulations in the modulation signal, wherein at least one of the modulation clock signals varies based on variations in a frequency of the variable frequency power transmission signal; and

a communication transmitter adapted to selectively affect the variable frequency power transmission signal according to the modulation signal, wherein the variable frequency power transmission signal is capable of varying in response to a change in at least one operating parameter of the inductive power supply, whereby the at least one of the one or more modulation clock signals is varied based on the change in the at least one operating parameter of the inductive power supply, and wherein the data stream from the variable frequency power transmission signal is decoded by time slicing the variable frequency power transmission signal and identifying DC offsets among time slices.

23. The system as claimed in claim 22 wherein a number of modulations in the modulation signal that are associated with each bit of the data stream varies based on changes in the one or more modulation clock signals.

24. The system as claimed in claim 22 wherein said remote device includes said communication transmitter such that said remote device communicates data to the inductive power supply using keyed modulation, and wherein said inductive power supply includes detector circuitry for decoding the data stream from the variable frequency power transmission signal.

25. The system as claimed in claim 22 wherein said inductive power supply includes said communication transmitter such that said inductive power supply communicates data to the remote device using said keyed modulation, and wherein said remote device includes detector circuitry for decoding the data stream from the variable frequency power transmission signal.

26. The system as claimed in claim 22 wherein said communication transmitter is configured to modulate a load, and wherein the load is modulated in the communication transmitter at a modulation clock frequency that is a fraction of the frequency of the variable frequency power transmission signal.

27. The system as claimed in claim 26 wherein the modulation clock frequency is one-half the frequency of the variable frequency power transmission signal.

28. The system as claimed in claim 26 wherein the load is toggled to increase a magnitude of every other waveform of the variable frequency power transmission signal.

29. The system as claimed in claim 26 wherein the load is toggled to increase a magnitude of the peak or the trough of every other waveform of the variable frequency power transmission signal.

30. The system as claimed in claim 29 wherein the load is toggled on every even waveform or every odd waveform.