Device alignment in inductive power transfer systems

Patent metadata

Field	Value
Publication number	US-9409490-B2
Application number	US-201314040496-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Sep 27, 2013
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

This disclosure provides systems, methods and apparatus for wireless power transfer and particularly wireless power transfer to remote systems such as electric vehicles. In one aspect, a wireless power receiver includes a first inductive element configured to receive wireless charging power from a transmitter. The wireless power receiver further includes a second inductive element, laterally separated from the first, configured to receive wireless charging power from the transmitter. The wireless power receiver further includes a position detector configured to determine a lateral position of the receiver relative to the transmitter based on characteristics of the first and second inductive elements.

First claim

What is claimed is:

1. A wireless power receiver comprising:
a first inductive element configured to receive wireless charging power from a transmitter;
a second inductive element, laterally separated from the first, configured to receive wireless charging power from the transmitter;
a switch configured to, intermittently, electrically couple a first node, common to both the first and second inductive elements, with a second node, common to both a first sensor and a second sensor;
the first sensor configured to measure a characteristic between one end of the first inductive element, opposite the first node, and the second node;
the second sensor configured to measure a characteristic between one end of the second inductive element, opposite the first node, and the second node; and
a position detector configured to determine a lateral position of the receiver relative to the transmitter based on the measured characteristics, and to provide at least one output for alignment of a vehicle comprising the wireless power receiver based on the determined lateral position.

2. The wireless power receiver of claim 1 , wherein at least one characteristic comprises an induced voltage at the first and second inductive elements.

3. The wireless power receiver of claim 1 , wherein the first and second inductive elements are electrically connected in series in a “double D” configuration.

4. The wireless power receiver of claim 3 , wherein the switch is configured to electrically partition the first and second inductive elements.

5. The wireless power receiver of claim 1 , further comprising a quadrature coil substantially between the first and second inductive elements.

6. The wireless power receiver of claim 1 , wherein the position detector is further configured to determine a longitudinal position of the receiver relative to the transmitter based on a gradient of a scalar alignment parameter.

7. The wireless power receiver of claim 1 , wherein the vehicle comprises an automatic alignment system configured to align the vehicle with respect to the transmitter based on the determined lateral position.

8. A method of detecting alignment at a wireless power receiver, comprising:
receiving wireless power at a first inductive element from a transmitter;
receiving wireless power at a second inductive element from the transmitter;
intermittently, electrically coupling a first node, common to both the first and second inductive elements, with a second node, common to both a first sensor and a second sensor;
measuring, at the first sensor, a characteristic between one end of the first inductive element, opposite the first node, and the second node;
measuring, at the second sensor, a characteristic between one end of the second inductive element, opposite the first node, and the second node; and
determining a lateral position of the receiver relative to the transmitter based on the measured characteristics; and providing at least one output for alignment of a vehicle comprising the wireless power receiver based on the determined lateral position.

9. The method of claim 8 , wherein at least one characteristic comprises an induced voltage at the first and second inductive elements.

10. The method of claim 8 , wherein the first and second inductive elements are electrically connected in series in a “double D” configuration.

11. The method of claim 10 , further comprising electrically partitioning the first and second inductive elements.

12. The method of claim 8 , further comprising receiving wireless power at a quadrature coil substantially between the first and second inductive elements.

13. The method of claim 8 , further comprising determining a longitudinal position of the receiver relative to the transmitter based on a gradient of a scalar alignment parameter.

14. The method of claim 8 , further comprising aligning the vehicle with respect to the transmitter based on the determined lateral position.

15. An apparatus for detecting alignment at a wireless power receiver, comprising:
a first inductive element configured to receive wireless charging power from a transmitter;
a second inductive element configured to receive wireless charging power from a transmitter;
means for, intermittently, electrically coupling a first node, common to both the first and second inductive elements, with a second node, common to both a first means for measuring and a second means for measuring;
the first means for measuring a characteristic between one end of the first inductive element, opposite the first node, and a second node;
the second means for measuring a characteristic between one end of the second inductive element, opposite the first node, and a second node; and
means for determining a lateral position of the receiver relative to the transmitter based on the measured characteristics; and means for providing at least one output for alignment of a vehicle comprising the wireless power receiver based on the determined lateral position.

16. The apparatus of claim 15 , wherein at least one characteristic comprises an induced voltage at the first and second inductive elements.

17. The apparatus of claim 15 , wherein the first and second inductive elements are electrically connected in series in a “double D” configuration.

18. The apparatus of claim 17 , further comprising means for electrically partitioning the first and second inductive elements.

19. The apparatus of claim 15 , further comprising a quadrature coil substantially between the first and second inductive elements.

20. The apparatus of claim 15 , further comprising means for determining a longitudinal position of the receiver relative to the transmitter based on a gradient of a scalar alignment parameter.

21. The apparatus of claim 15 , further comprising means for aligning the vehicle with respect to the transmitter based on the determined lateral position.

22. A non-transitory computer-readable medium comprising code that, when executed, causes a wireless charging apparatus to:
receive wireless power at a first inductive element from a transmitter;
receive wireless power at a second inductive element from the transmitter;
intermittently, electrically couple a node common to both the first and second inductive elements, with a second node, common to both a first sensor and a second sensor;
measure, at the first sensor, a characteristic between one end of the first inductive element, opposite the first node, and the second node;
measure, at the second sensor, a characteristic between one end of the second inductive element, opposite the first node, and the second node; and
determine a lateral position of the receiver relative to the transmitter based on the measured characteristics; and provide at least one output for alignment of a vehicle comprising the wireless charging apparatus based on the determined lateral position.

23. The medium of claim 22 , wherein at least one characteristic comprises an induced voltage at the first and second inductive elements.

24. The medium of claim 22 , wherein the first and second inductive elements are electrically connected in series in a “double D” configuration.

25. The medium of claim 24 , further comprising code that, when executed, causes the apparatus to electrically partition the first and second inductive elements.

26. The medium of claim 22 , further comprising code that, when executed, causes the appa

Assignees

• Qualcomm Inc

Inventors

• Kawashima Kiyotaka

Classifications

• G01B2210/58

  Wireless transmission of information between a sensor or probe and a control or evaluation unit · CPC title

• Y04S30/12

  Remote or cooperative charging · CPC title

• B60L53/36

  by positioning the vehicle · CPC title

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title

• B60L53/126

  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 title