SYSTEM AND METHOD OF PROVIDING COMMUNICATIONS IN A WIRELESS POWER TRANSFER SYSTEM

• US 20160294445A1
• Filed: 06/14/2016
• Published: 10/06/2016
• Est. Priority Date: 02/07/2011
• Status: Active Grant

• Current Assignee: Philips IP Ventures B.V. (Koninklijke Philips N.V.)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• 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.
• Granted Patent: US 10,277,279 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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.

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 the modulation frequency

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 the 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 further comprising decoding the data stream from the variable frequency power transmission signal by timeslicing the variable frequency power transmission signal and comparing the DC offset between two time slices.

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

toggling the modulation 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 11 further comprising decoding the data stream from the variable frequency power transmission signal by timeslicing the variable frequency power transmission signal and identifying DC offsets among the time slices.

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

16. A remote device for transferring power to a remote device from an inductive power supply and for communicating data from the remote device 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; and

a communication transmitter adapted to selectively toggle a load on the variable frequency power transmission signal according to the modulation signal.

17. The remote device as claimed in claim 16 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.

18. The remote device as claimed in claim 16 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.

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

20. The remote device as claimed in claim 18 wherein the load is toggled to increase a magnitude of every other waveform of the variable frequency power transmission signal.

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

22. The remote device as claimed in claim 18 wherein the load is toggled to increase the magnitude of the peak or the trough of every other waveform of the variable frequency power transmission signal.

23. 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.

24. The system as claimed in claim 23 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.

25. The system as claimed in claim 23 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.

26. The system as claimed in claim 23 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.

27. The system as claimed in claim 23 wherein said communication transmitter is configured to modulate said 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.

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

29. The system as claimed in claim 27 wherein the load is toggled to increase a magnitude of every other waveform of the variable frequency power transmission signal.

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

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