Method and apparatus for pre-alignment of an automatically aligning magnetic field system

Patent metadata

Field	Value
Publication number	US-12294227-B2
Application number	US-202318153991-A
Country	US
Kind code	B2
Filing date	Jan 12, 2023
Priority date	Jan 13, 2022
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

A wireless power transfer system includes a wireless power transfer device configured to determine a magnetic field, from among a plurality of directionally different potential magnetic fields that the wireless power transfer device is configured to generate, that has, at a receiver coil of an electronic device, a direction aligned with the receiver coil.

First claim

What is claimed is:

1. A wireless power transfer system comprising:
a wireless power transfer device, the wireless power transfer device comprising:
a first transmitting coil oriented along a first axis,
a second transmitting coil on the first transmitting coil, oriented along a second axis different from the first axis, and spaced, in an area of overlap between the first and second transmitting coils, from the first transmitting coil along a third direction perpendicular to both the first and second axes,
a non-magnetic material between the first and second transmitting coils along the third direction and in the area of overlap such that the second transmitting coil is magnetically decoupled from the first transmitting coil in the area of overlap, and
a controller configured to differentially control driving of the first and second transmitting coils,

wherein the controller is configured to determine an amplitude ratio such that, in response to the first transmitting coil being driven with a first current having a first amplitude, the second transmitting coil being driven with a second current having a second amplitude, and a ratio of the first amplitude to the second amplitude is the amplitude ratio, the wireless power transfer device generates a magnetic field having a direction, at a receiver coil of an electronic device, that is aligned with the receiver coil.

2. The wireless power transfer system of claim 1 , wherein the wireless power transfer device comprises a first inertial measurement unit (IMU) configured to measure a gravity orientation of the first and second transmitting coils relative to a gravity vector, and the controller is configured to determine the amplitude ratio based on the gravity orientation of the first and second transmitting coils.

3. The wireless power transfer system of claim 2 , wherein the electronic device comprises:
a second IMU sensor configured to measure a gravity orientation of the receiver coil relative to a gravity vector; and
a transmitter configured to transmit information about the gravity orientation of the receiver coil to the wireless power transfer device, and
wherein the controller is configured to determine the amplitude ratio based on the gravity orientation of the first and second transmitting coils and the gravity orientation of the receiver coil.

4. The wireless power transfer system of claim 2 , wherein the electronic device is an implantable medical device, and the controller is configured to determine the amplitude ratio based on the gravity orientation of the first and second transmitting coils and a bodily orientation of the receiver coil relative to a body in which the electronic device is implanted.

5. The wireless power transfer system of claim 4 , wherein:
the wireless power transfer device comprises a first memory and is configured to receive, and to store in the first memory, information about the bodily orientation of the receiver coil, or
the electronic device comprises a second memory, is configured to receive, and to store in the second memory, information about the bodily orientation of the receiver coil, and comprises a transmitter configured to transmit the information about the bodily orientation of the receiver coil to the wireless power transfer device.

6. The wireless power transfer system of claim 2 , wherein the controller is configured to determine the amplitude ratio based on the gravity orientation of the first and second transmitting coils and information about a prior operation, the information about the prior operation comprising:
Information about a prior gravity orientation of the first and second transmitting coils; and
Information about a prior amplitude ratio of an amplitude of a prior first current to an amplitude of a prior second current, the prior first current and the prior second current being utilized during the prior operation to respectively drive the first and second transmitting coils, while the first and second transmitting coils had the prior gravity orientation, to generate a prior magnetic field having a direction at the receiver coil that was aligned with the receiver coil.

7. The wireless power transfer system of claim 1 , wherein the electronic device is an implantable medical device, and
wherein the wireless power transfer device is configured to couple to a body in which the implantable medical device is implanted such that, when the wireless power transfer device is so coupled to the body, the first and second transmitting coils have a substantially fixed bodily orientation relative to the body.

8. The wireless power transfer system of claim 7 , wherein the controller is configured to determine the amplitude ratio based on the bodily orientation of the first and second transmitting coils and a bodily orientation of the receiver coil relative to the body.

9. The wireless power transfer system of claim 7 , wherein the controller is configured to determine the amplitude ratio based on the bodily orientation of the first and second transmitting coils and information about a prior operation, the information about the prior operation comprising a prior amplitude ratio of an amplitude of a prior first current to an amplitude of a prior second current, the prior first current and the prior second current being utilized during the prior operation to respectively drive the first and second transmitting coils to generate a prior magnetic field having a direction at the receiver coil aligned with the receiver coil.

10. The wireless power transfer system of claim 7 , wherein the wireless power transfer device comprises a coil assembly comprising the first and second transmitting coils and an electronics assembly comprising at least one electronics component and being coupled to the coil assembly via a cable, and
wherein the wireless power transfer device is configured to be fitted over a neck of the body so that the coil assembly is positioned over a front or a back of the body with a substantially fixed orientation relative to the body.

11. The wireless power transfer system of claim 1 , wherein the controller is configured to determine, together with the amplitude ratio, a relative phase difference such that, in response to the first and second transmitting coils being respectively driven with the first and second currents, and the first and second currents being phase shifted relative to each other by the relative phase difference, the wireless power transfer device generates the magnetic field having the direction, at the receiver coil, that is aligned with the receiver coil.

12. The wireless power transfer system of claim 1 , wherein the wireless power transfer device comprises:
a first current sensor configured to measure current in the first transmitting coil;
a first driver configured to provide current to the first transmitting coil based on a first bus voltage;
a first variable power supply configured to provide the first bus voltage to the first driver;
a second current sensor configured to measure current in the second transmitting coil;
a second driver configured to provide current to the second transmitting coil based on a second bus voltage;
a second variable power supply configured to provide the second bus voltage to the second driver; and
wherein the controller is configured to differentially control the driving of the first and second transmitting coils to generate a plurality of directionally different preliminary magnetic fields and to generate, for each of the plurality of preliminary magnetic fields, a corresponding comparison between:
a corresponding preliminary voltage ratio of a corresponding first preliminary bus voltage provided by th

Assignees

• The Alfred E Mann Foundation For Scient Research
• The Alfred Mann Foundation For Scient Research

Inventors

• Dearden Brian
• Shelton Brian
• Farkas Leslie G

Classifications

• H02J50/90

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

• G01R19/0092

  Measuring current only · CPC title

• G01P15/02

  by making use of inertia forces {using solid seismic masses}(G01P15/14 takes precedence) · CPC title

• H02J50/12

  of the resonant type · CPC title

• H02J50/80

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title