Guidance and alignment system and methods for electric vehicle wireless charging systems

• US 9,739,844 B2
• Filed: 10/15/2014
• Issued: 08/22/2017
• Est. Priority Date: 07/25/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hans Peter, Sieber, Lukas, Daetwyler, Andreas
• Primary Examiner(s): Nguyen, Tung X
• Assistant Examiner(s): HAWKINS, DOMINIC E
• Application Number:
  US14/515,291
• Publication Number:
  US 20160025821A1
• Time in Patent Office: 1,042 Days
• Field of Search: 324258, 324259, 324244, 324200
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: G01R 33/0047 Housings or packaging of magnetic sensors packaging of semiconductor devices H01L23/00; Holders
• CPC Class Codes: G01R 33/0206 Three-component magnetometers
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

Guidance and alignment systems are disclosed for wireless charging systems to assist in aligning the transmitter and receiver inductive power transfer (IPT) couplers. These systems guide positioning and alignment to provide sufficient coupling between the transmitter and receiver IPT couplers. Exemplary systems provide a magnetic field sensor, magnetic field generator, and magnetic vectoring to determine a position of an electric vehicle or a wireless charging base. In a magnetic vectoring system, an alignment system comprising at least three coils (or similar circuits) on a magnetically permeable substrate receives a positioning magnetic field including modulated information signals and processes the received signal to generate an output for determining a position of the positioning magnetic field source relative to the magnetic field sensor position. The alignment system may further comprise a similar structure that generates the positioning magnetic field, that may include modulated information signals, based on input signals.

Claims

1. An apparatus for sensing magnetic field components in a wireless power transfer system, comprising:

a ferromagnetic magnetically permeable substrate;

at least three co-planar coils configured to generate signals induced by a received magnetic field, the at least three coils disposed on the ferromagnetic magnetically permeable substrate, the ferromagnetic magnetically permeable substrate configured to alter the magnetic field that flows through the at least three coils;

a conductive back plate disposed on the ferromagnetic magnetically permeable substrate on a side opposite the at least three co-planar coils; and

a processing system operably connected to the coils and configured to generate at least two outputs, based on the signals generated by the coils, the outputs indicative of at least two vector components of the received magnetic field.

2. The apparatus of claim 1, wherein the processing system comprises a signal combiner and a detector to provide a vector output, the signal combiner configured to combine the signals generated by the coils and the detector configured to perform a non-linear operation on the signals to generate the vector output.

3. The apparatus of claim 2, wherein the signal combiner is configured to combine signals to produce a vector component of the vector output that is a maximum when a direction of the received magnetic field is perpendicular to a plane of the at least three coils.

4. The apparatus of claim 2, wherein the signal combiner is configured to combine signals to produce a vector component of the vector output that is a maximum when a direction of the received magnetic field is parallel to a plane of the at least three coils.

5. The apparatus of claim 2, wherein the signal combiner combines signals from a combination of at least two coils of the at least three coils to produce at least one of an x-, y-, or z-vector component output.

6. The apparatus of claim 1, wherein the at least three coils are positioned in a geometry providing at least one symmetry axis.

7. The apparatus of claim 1, wherein the one or more of the coils of the at least three coils overlap with another coil of the at least three coils.

8. The apparatus of claim 1, wherein the processing system is configured to generate three outputs based on the signals generated by the at least three coils, wherein each of the three outputs is indicative of one of the three vector components (Vx, Vy, Vz) of the received magnetic field.

9. The apparatus of claim 1, wherein the conductive back plate is configured to reduce a sensitivity of the at least three coils to the environment.

10. The apparatus of claim 1, wherein the at least three coils are positioned within or on a printed circuit board.

11. The apparatus of claim 10, wherein the printed circuit board, the at least three coils, and the ferromagnetic magnetically permeable substrate are positioned within an inductive power transfer coupler configured to perform inductive power transfer.

12. The apparatus of claim 1, wherein the ferromagnetic magnetically permeable substrate and the at least three co-planar coils are configured to be positioned within an inductive power transfer coupler configured to perform inductive power transfer.

13. A method of sensing magnetic field components in a wireless power transfer system, comprising:

receiving a magnetic field via at least three co-planar coils disposed on a ferromagnetic magnetically permeable substrate;

altering, via the ferromagnetic magnetically permeable substrate, the magnetic field that flows through the at least three co-planar coils;

generating signals induced by the received magnetic field via the at least three coils; and

generating, via a processing system, at least two outputs based on the signals generated by the at least three coils, the output comprising at least two vector components of the received magnetic field, wherein a conductive back plate is positioned on the ferromagnetic magnetically permeable substrate opposite of the coils.

14. The method of claim 13, wherein generating the at least two outputs comprises combining, via a signal combiner, signals generated by the at least three coils and performing non-linear operations on the signals to generate the vector output via a detector.

15. The method of claim 14, wherein combining signals generated by the at least three coils comprises combining the signals to produce a vector component of the vector output that is a maximum when a direction of the received magnetic field is perpendicular to a plane of the at least three coils.

16. The method of claim 14, wherein combining signals generated by the at least three coils comprises combining the signals to produce a vector component of the vector output that is a maximum when a direction of the received magnetic field is parallel to a plane of the at least three coils.

17. The method of claim 14, wherein combining signals comprises combining signals from a combination of at least two coils of the at least three coils to produce at least one of an x-, y-, or z-vector component output.

18. The method of claim 14, wherein performing non-linear operations comprises detecting at least one of an amplitude, signal level, and magnitude of a complex phase to obtain the output.

19. The method of claim 13, further comprising positioning the at least three coils in a geometry providing at least one symmetry axis.

20. The method of claim 13, further comprising positioning one or more of the at least three coils such that it overlaps with at least one other of the at least three coils.

21. The method of claim 13, wherein generating at least one output comprises generating three outputs based on the signals generated by the at least three coils, wherein each of the three outputs is indicative of one of the three vector components (Vx, Vy, Vz) of the received magnetic field.

22. The method of claim 13, further comprising electrically insulating and mechanically protecting the at least three coils positioned within or on a circuit board substrate.

23. The method of claim 22, wherein the ferromagnetic magnetically permeable substrate, the circuit board substrate, and the at least three co-planar coils are configured to be positioned within an inductive power transfer coupler configured to perform inductive power transfer.

24. The method of claim 13, wherein the ferromagnetic magnetically permeable substrate and the at least three co-planar coils are configured to be positioned within an inductive power transfer coupler configured to perform inductive power transfer.

25. The method of claim 13, further comprising reducing a sensitivity of the at least three coils to the environment via the conductive back plate.

26. An apparatus for sensing magnetic field components in a wireless power transfer system, comprising

at least three co-planar coils disposed on a ferromagnetic magnetically permeable substrate, configured to generate signals induced by a received magnetic field, the ferromagnetic magnetically permeable substrate configured to alter the magnetic field that flows through the at least three coils;

means for reducing a sensitivity of the at least three coils to an environment, the means for reducing a sensitivity positioned on the ferromagnetic magnetically permeable substrate opposite the coils; and

means for generating at least two outputs based on the signals generated by the at least three co-planar coils, the output comprising at least two vector components of the received magnetic field.

27. The apparatus of claim 26, wherein the output generating means comprises means for combining signals generated by the at least three coils, and means for performing non-linear operations on the signals to generate the vector output.

28. The apparatus of claim 27, wherein the combining means comprising means for combining the signals to provide a vector component of the vector output that is a maximum when a direction of the received magnetic field is perpendicular to a plane of the at least three coils.

29. The apparatus of claim 27, wherein the combining means comprising means for combining the signals to provide a vector component of the vector output that is a maximum when a direction of the received magnetic field is parallel to a plane of the at least three coils.

30. The apparatus of claim 27, wherein the combining means comprising means for combining signals from a combination of at least two coils of the at least three coils to produce at least one of a x-, y-, or z-vector component output.