System and method of inductive charging and localization through using multiple primary inductive coils to detect the induced voltage of a secondary inductive coil

• US 9,425,640 B2
• Filed: 10/24/2013
• Issued: 08/23/2016
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Moran, James E.
• Primary Examiner(s): Grant, Robert
• Assistant Examiner(s): TRISCHLER, JOHN T
• Application Number:
  US14/062,045
• Publication Number:
  US 20150084585A1
• Time in Patent Office: 1,034 Days
• Field of Search: 320/108, 307/104
• US Class Current: 1/1
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries

Abstract

According one aspects, embodiments herein provide an inductive localization and charging system for detecting and charging a medical device comprising a plurality of primary inductive coils arranged within a dielectric material, an input connector coupled to the plurality of primary inductive coils and configured to receive input power, a controller coupled to the plurality of primary inductive coils and to the input connector, the controller configured to selectively activate each primary coil of the plurality of primary inductive coils, determine that a first primary coil of the plurality of primary inductive coils is within operable proximity of an external secondary coil located in the medical device, and control transfer of power between the primary coil and the secondary coil to charge the medical device.

Claims

1. An inductive localization and charging system for detecting and charging a device, the system comprising:

a plurality of primary inductive coils arranged within a dielectric material;

an input connector coupled to the plurality of primary inductive coils and configured to receive input power;

a controller coupled to the plurality of primary inductive coils and to the input connector, the controller configured to;

selectively activate each primary coil of the plurality of primary inductive coils during a dwell time;

measure a first voltage value for each activated primary coil of the plurality of primary inductive coils during the dwell time;

determine whether the first voltage value is above a reference threshold voltage;

set a flag indicating one or more activated primary coils is within operable proximity of a secondary coil in response to the determination that the first voltage value is above the reference threshold voltage;

adjust the reference threshold voltage to decrease sensitivity in response to the flag indicating that two or more activated primary coils are within proximity of a secondary coil;

determine that a first primary coil of the plurality of primary inductive coils is within operable proximity of an external secondary coil located in the device; and

control transfer of power between the first primary coil and the secondary coil to charge the device.

2. The system of claim 1, wherein each primary coil of the plurality of primary inductive coils is wound opposite of adjacent primary coils.

3. The system of claim 1, wherein the controller is configured to adjust the reference threshold voltage to increase sensitivity in response to the flag indicating that no activated primary coil is within operable proximity of a secondary coil.

4. The system of claim 1, wherein the controller is further configured to decode a signal from an activated primary coil based on load shift keying (LSK).

5. The system of claim 1, wherein the controller is further configured to suspend the transfer of power to the secondary coil based on an LSK data transmission.

6. The system of claim 1, wherein the dielectric material is a top sheet of a bed.

7. The system of claim 1, wherein the plurality of primary inductive coils are organized in an array, having rows and columns.

8. The system of claim 7, wherein the plurality of primary inductive coils are configured according to a modified star grounding configuration, wherein the array is comprised of a plurality of primary coil rows, and wherein each primary coil row of the plurality of primary coil rows is coupled to a common return line.

9. A method of detecting and charging a device, the method comprising:

activating each primary coil of a plurality of primary inductive coils during a dwell time;

measuring a first voltage value for each activated primary coil of the plurality of primary inductive coils during the dwell time;

determining whether the first voltage value is above a reference threshold voltage;

setting a flag indicating one or more activated primary inductive coils is within operable proximity of a secondary coil in response to the determination that the first voltage value is above the reference threshold voltage;

adjusting the reference threshold voltage to decrease sensitivity in response to the flag indicating that two or more activated primary coils are within proximity of a secondary coil;

determining that a first primary coil of the plurality of primary inductive coils is within operable proximity of an external secondary coil located in the device;

controlling a transfer of power between the first primary coil and the secondary coil to charge the device.

10. The method of claim 9, wherein setting the flag further includes adjusting the reference threshold voltage to increase sensitivity in response to the flag indicating that no activated primary coils is within operable proximity of a secondary coil.

11. The method of claim 9, wherein determining that a first primary coil of the plurality of primary inductive coils is within operable proximity of an external secondary coil further includes decoding a signal from an activated primary coil based on load shift keying (LSK).

12. The method of claim 9, the method further comprising:

determining that no activated primary coil is within operable proximity of a secondary coil; and

suspending processing for a predetermined period of time.