Device, system and method for detection of a foreign object

Patent metadata

Field	Value
Publication number	US-11685269-B2
Application number	US-201917046574-A
Country	US
Kind code	B2
Filing date	Apr 17, 2019
Priority date	Apr 19, 2018
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

A detection device includes a detection mat having a plurality of detection coils, and at least one pair of groups of detection coils, the pair of groups of detection coils includes first and second groups of detection coils. The first and second group of detection coils comprises first and second first and second impedance values. The detection device includes one or more drive sub-systems and a comparison sub-system. The drive sub-systems are operatively coupled to the detection mat and configured to excite at least one pair of groups of detection coils. The comparison sub-system is operatively coupled to the detection mat and configured to receive a differential current signal from the pair of groups of detection coils, the comparison subsystem is configured to generate a control signal based on the differential current signal.

First claim

We claim:

1. A detection device, comprising:
a detection mat having at least one pair of groups of detection coils, the at least one pair of groups of detection coils including a first group of detection coils having a first impedance value and a second group of detection coils having a second impedance value, wherein the first and second impedance values are dissimilar to one another;
one or more drive sub-systems operatively coupled to the detection mat and configured to excite at least one pair of groups of detection coils using different voltage signals provided to the first and second groups of detection coils such that the first and second groups of detection coils are driven by corresponding currents having substantially similar magnitude and phase in the absence of a foreign object; and
a comparison sub-system operatively coupled to the detection mat and configured to generate a control signal indicating a presence of the foreign object based on a differential current signal from the at least one pair of groups of detection coils.

2. The detection device of claim 1 , wherein the first and second groups of detection coils comprise structurally similar arrangement of detection coils.

3. The detection device of claim 1 , wherein the first and second groups of detection coils are disposed at a same geometric region on the detection mat.

4. The detection device of claim 1 , wherein the one or more drive sub-systems comprise two drive units coupled respectively to the first and second groups of detection coils and at least one drive controller, and wherein the drive controller is coupled to the two drive units.

5. The detection device of claim 1 , wherein the detection mat includes a plurality of detection coils comprises associated with a plurality of detection zones, wherein each of the plurality of detection zones comprises one or more groups of detection coils.

6. The detection device of claim 5 , wherein at least a portion of the one or more drive sub-systems is configured to be coupled to two or more detection zones of the plurality of detection zones.

7. The detection device of claim 6 , wherein detection zones of the plurality of detection zones corresponding to a pair of detection zones comprise structurally identical arrangement of detection coils.

8. The detection device of claim 1 , wherein the detection mat is a flexible mat, a conformable mat, a rigid mat, or a plug and play mat.

9. The detection device of claim 1 , wherein the detection mat includes a plurality of detection coils, and wherein the plurality of detection coils comprise concentric coils, adjacently disposed coils, a side-by-side arrangement of coils, and wherein the plurality of detection coils are disposed in one or more layers.

10. The detection device of claim 1 , wherein the comparison sub-system comprises:
an electrical winding and a magnetic core configured to receive the differential current signal from the first and second groups of detection coils, and generate a detection voltage signal based on the differential current signal; and
a comparator configured to compare the detection voltage signal with a threshold voltage signal to generate the control signal.

11. The detection device of claim 1 , further comprising:
a mechanical wear resistant material suitable to withstand movement of an electric vehicle over the detection device when the detection device is placed on a surface area of a transmitter unit.

12. The detection device of claim 1 , wherein the detection device is configured to be disposed in an operative environment of a wireless power transfer (WPT) system, the detection device further comprising:
a communication unit configured to communicate the control signal to the WPT system to indicate the presence of the foreign object before or during wireless power transfer.

13. The detection device of claim 12 , wherein the communication unit is configured to communicate the control signal to control unit associated with a transmitter unit of a wireless power transfer (WPT) system, an operator of an electric vehicle (EV) associated with the WPT system, an operator of an EV charging station associated with the WPT system, or any combination thereof.

14. The detection device of claim 12 , wherein the communication unit is configured to communicate the control signal via a mobile phone network.

15. A method comprising:
utilizing a detection device, including a detection mat having at least one pair of groups of detection coils, the at least one pair of groups of detection coils including a first group of detection coils having a first impedance value and a second group of detection coils having a second impedance value, wherein the first and second impedance values are dissimilar to one another;
exciting at least one pair of groups of detection coils using different voltage signals provided to the first and second groups of detection coils such that the first and second groups of detection coils are driven by corresponding currents having substantially similar magnitude and phase in the absence of a foreign object;
determining a differential current signal from the at least one pair of groups of detection coils; and
generating a control signal indicating a presence of the foreign object based on the differential current signal.

16. The method of claim 15 , further comprising transmitting the control signal to a transmitter unit configured to control transmission of wireless power based on the control signal.

17. The method of claim 16 , further comprising:
generating a detection voltage signal based on the differential current signal; and
comparing the detection voltage signal with a threshold voltage signal to generate the control signal.

18. The method of claim 15 , wherein exciting the at least one pair of groups of detection coils comprises exciting the at least one pair of groups of detection coils intermittently, or at a periodic interval.

19. The method of claim 15 , wherein exciting the at least one pair of groups of detection coils comprises exciting groups of detection coils corresponding to different pairs of groups of detection coils at different instances in time.

Assignees

• Gen Electric

Inventors

• Kanakasabai Viswanathan
• Aravind Deepak
• Bhat Suma Memana Narayana
• Bohori Adnan Kutubuddin

Classifications

• B60L53/124 Primary

  Detection or removal of foreign bodies · CPC title

• H02J50/60 Primary

  responsive to the presence of foreign objects, e.g. detection of living beings · CPC title

• G01V3/104 Primary

  using several coupled or uncoupled coils (G01V3/101 takes precedence) · CPC title

• H02J50/10

  using inductive coupling · CPC title

• B60Y2200/92

  Hybrid vehicles · CPC title