SYSTEMS, METHODS, AND APPARATUS FOR DETECTING METALLIC OBJECTS IN A PREDETERMINED SPACE VIA INDUCTIVE KINEMATIC SENSING

• US 20170097437A1
• Filed: 02/10/2016
• Published: 04/06/2017
• Est. Priority Date: 10/05/2015
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hans Peter, Daetwyler, Andreas, Sieber, Lukas
• Granted Patent: US 10,298,049 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• CPC Class Codes: B60L 53/124 Detection or removal of foreign bodies
• 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: G01D 5/2006 by influencing the self-induction of one or more coils G01D5/22 takes precedence
• CPC Class Codes: G01V 3/101 by measuring the impedance of the search coil; by measuring features of a resonant circuit comprising the search coil measuring impedance or characteristics derived therefrom G01R27/00, e.g. quality factor G01R27/26
• 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 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• 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

An apparatus for detecting a presence of an object is provided. The apparatus comprises an inductive sensing coil that is configurable to generate a magnetic field, the inductive sensing coil configured to have an electrical characteristic that is detectable when generating the magnetic field. The apparatus comprises an actuator configured to inducing relative motion between the inductive sensing coil and the object while the inductive sensing coil generates the magnetic field. The apparatus comprises a controller configured to detect a change in the electrical characteristic, and determine a presence of the object based on the change in the electrical characteristic correlating with the relative motion between the inductive sensing coil and the object. The electrical characteristic comprises one or more of an equivalent resistance, an equivalent inductance, an equivalent impedance, and an impulse response of the inductive sensing coil.

Claims

1. An apparatus for detecting an object, comprising:

an inductive sensing coil that is configurable to generate a magnetic field, the inductive sensing coil configured to have an electrical characteristic that is detectable when generating the magnetic field;

an actuator configured to induce relative motion between the inductive sensing coil and the object while the inductive sensing coil generates the magnetic field; and

a controller configured to;

detect a change in the electrical characteristic, and

determine a presence of the object based on the change in the electrical characteristic correlating with the relative motion between the inductive sensing coil and the object.

2. The apparatus of claim 1, wherein the electrical characteristic comprises one or more of an equivalent resistance, an equivalent inductance, an equivalent impedance, and an impulse response of the inductive sensing coil.

3. The apparatus of claim 1, wherein the object comprises one or more of a metallic object, a metallic film and a metallic foil.

4. The apparatus of claim 1, wherein the inductive sensing coil comprises a plurality of inductive sensing coils and wherein the controller is further configured to multiplex measurements of a plurality of changes in the electrical characteristic of the plurality of inductive sensing coils.

5. The apparatus of claim 1, wherein the controller is further configured to reduce sensitivity to detection of dielectric objects by applying a first scaling factor to a real component of a voltage induced across the inductive sensing coil while the inductive sensing coil generates the magnetic field, and by applying a second scaling factor to an imaginary component of the voltage.

6. The apparatus of claim 1, further comprising an inductive power transfer coil having a fixed position relative to the inductive sensing coil.

7. The apparatus of claim 1, wherein the controller is configured to detect the change in the electrical characteristic in the time domain.

8. The apparatus of claim 1, wherein the motion of the inductive sensing coil is substantially sinusoidal in at least one of 3 mutually orthogonal directions.

9. A method for detecting an object, comprising:

generating a magnetic field via an inductive sensing coil configured to have an electrical characteristic that is detectable when generating the magnetic field,

inducing relative motion between the inductive sensing coil and the object while the inductive sensing coil generates the magnetic field,

detecting a change in the electrical characteristic, and

determining a presence of the object based on the change in the electrical characteristic correlating with the relative motion between the inductive sensing coil and the object.

10. The method of claim 9, wherein the electrical characteristic comprises one or more of an equivalent resistance, an equivalent inductance, an equivalent impedance, and an impulse response of the inductive sensing coil.

11. The method of claim 9, wherein the object comprises one or more of a metallic object, a metallic film and a metallic foil.

12. The method of claim 9, wherein the inductive sensing coil comprises a plurality of inductive sensing coils, the method further comprising multiplexing measurements of a plurality of changes in the electrical characteristic of the plurality of inductive sensing coils.

13. The method of claim 9, further comprising reducing sensitivity to detection of dielectric objects by applying a first scaling factor to a real component of a voltage induced across the inductive sensing coil while the inductive sensing coil generates the magnetic field, and applying a second scaling factor to an imaginary component of the voltage.

14. The method of claim 9, further comprising maintaining a fixed position of an inductive power transfer coil relative to the inductive sensing coil.

15. The method of claim 9, wherein the motion of the inductive sensing coil is substantially sinusoidal in at least one of 3 mutually orthogonal directions.

16. A non-transitory, computer-readable medium comprising code that, when executed, causes an apparatus for detecting an object to:

generate a magnetic field via an inductive sensing coil configured to have an electrical characteristic that is detectable when generating the magnetic field,

induce relative motion between the inductive sensing coil and the object while the inductive sensing coil generates the magnetic field,

detect a change in the electrical characteristic, and

determine a presence of the object based on the change in the electrical characteristic correlating with the relative motion between the inductive sensing coil and the object.

17. The medium of claim 16, wherein the electrical characteristic comprises one or more of an equivalent resistance, an equivalent inductance, an equivalent impedance, and an impulse response of the inductive sensing coil.

18. The medium of claim 16, wherein the object comprises one or more of a metallic object, a metallic film and a metallic foil.

19. The medium of claim 16, wherein the inductive sensing coil comprises a plurality of inductive sensing coils, the code, when executed, further causing apparatus to multiplex measurements of a plurality of changes in the electrical characteristic of the plurality of inductive sensing coils.

20. The medium of claim 16, wherein the code, when executed, further causes the apparatus to reduce sensitivity to detection of dielectric objects by applying a first scaling factor to a real component of a voltage induced across the inductive sensing coil while the inductive sensing coil generates the magnetic field, and applying a second scaling factor to an imaginary component of the voltage.

21. The medium of claim 16, wherein the code, when executed, further causes the apparatus to maintain a fixed position of an inductive power transfer coil relative to the inductive sensing coil.

22. The medium of claim 16, wherein the motion of the inductive sensing coil is substantially sinusoidal in at least one of 3 mutually orthogonal directions.

23. An apparatus for detecting an object, comprising:

means for generating a magnetic field, the means for generating the magnetic field configured to have an electrical characteristic that is detectable when generating the magnetic field;

means for inducing relative motion between the means for generating the magnetic field and the object while generating the magnetic field;

means for detecting a change in the electrical characteristic; and

means for determining a presence of the object based on the change in the electrical characteristic correlating with the relative motion between the means for generating the magnetic field and the object.

24. The apparatus of claim 23, wherein the electrical characteristic comprises one or more of an equivalent resistance, an equivalent inductance, an equivalent impedance, and an impulse response of the means for generating a magnetic field.

25. The apparatus of claim 23, wherein the object comprises one or more of a metallic object, a metallic film and a metallic foil.

26. The apparatus of claim 23, wherein the means for generating the magnetic field comprises a plurality of inductive sensing coils, the apparatus further comprising means for multiplexing measurements of a plurality of changes in the electrical characteristic of the plurality of inductive sensing coils.

27. The apparatus of claim 23, further comprising:

means for applying a first scaling factor to a real component of a voltage induced across the means for generating the magnetic field; and

means for applying a second scaling factor to an imaginary component of the voltage to reduce sensitivity to detection of dielectric objects.

28. The apparatus of claim 23, further comprising an inductive power transfer coil having a fixed position relative to the means for generating the magnetic field.

29. The apparatus of claim 23, further comprising means for detecting the change in the electrical characteristic in the time domain.

30. The apparatus of claim 23, wherein the motion of the means for generating the magnetic field is substantially sinusoidal in at least one of 3 mutually orthogonal directions.