SYSTEMS, METHODS, AND APPARATUS FOR DETECTION OF METAL OBJECTS IN A PREDETERMINED SPACE

• US 20140015522A1
• Filed: 03/08/2013
• Published: 01/16/2014
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: Qualcomm, Inc.
• Inventors: Widmer, Hanspeter, Sieber, Lukas, Bittner, Markus, Fischer, Marcel
• Granted Patent: US 9,410,823 B2
• Time in Patent Office: Days
• US Class Current: 324/239
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2200/22 Microcars, e.g. golf cars
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/525 Temperature of converter or components thereof
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• CPC Class Codes: B60L 2270/32 of electricity
• CPC Class Codes: B60L 2270/34 of parts
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0038 relating to sensors
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• CPC Class Codes: B60L 50/66 Arrangements of batteries
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• 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: B60L 53/30 : Constructional details of charging stations
• CPC Class Codes: B60L 53/305 : Communication interfaces
• CPC Class Codes: B60L 53/36 : by positioning the vehicle
• CPC Class Codes: B60L 53/37 : using optical position determination, e.g. using cameras
• CPC Class Codes: B60L 53/63 : in response to network capacity
• CPC Class Codes: B60L 53/65 : involving identification of vehicles or their battery types
• CPC Class Codes: B60L 53/68 : Off-site monitoring or control, e.g. remote control
• CPC Class Codes: B60L 55/00 : Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: B60L 58/10 : for monitoring or controlling batteries
• CPC Class Codes: G01D 5/2006 : by influencing the self-induction of one or more coils G01D5/22 takes precedence
• CPC Class Codes: G01N 27/725 : by using magneto-acoustical effects or the Barkhausen effect
• CPC Class Codes: G01V 3/10 : using induction coils
• 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: 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: Y02E 60/00 : Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• 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 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/12 : Remote or cooperative charging
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

This disclosure provides systems, methods and apparatus for detecting foreign objects. In one aspect an apparatus for detecting a presence of an object in a magnetic field is provided. The apparatus includes a power circuit configured to generate the magnetic field and transfer power wirelessly at a level sufficient to power or charge a load via the magnetic field. The apparatus further includes a detection circuit configured to transmit signals and detect, based on a reflection of the transmitted signals, a frequency of vibration of the object caused by the magnetic field.

Claims

1. An apparatus for detecting a presence of an object in a magnetic field, the apparatus comprising:

a power circuit configured to generate the magnetic field and transfer power wirelessly at a level sufficient to power or charge a load via the magnetic field; and

a detection circuit configured to transmit signals and detect, based on a reflection of the transmitted signals, a frequency of vibration of the object caused by the magnetic field.

2. The apparatus of claim 1, wherein the power circuit comprises an antenna, the power circuit configured to apply an alternating current to the antenna at a frequency to generate the magnetic field, and wherein the detection circuit is configured to detect that the object is a metal object based on the frequency of vibration.

3. The apparatus of claim 2, wherein the detection circuit is configured to detect that the object is a metal object in response to the detecting that the frequency of vibration is substantially twice the frequency of the alternating current.

4. The apparatus of claim 1, wherein the signal comprises a microwave carrier signal and wherein the detection circuit is configured to detect the frequency of vibration based on a micro-Doppler effect.

5. The apparatus of claim 4, wherein the detection circuit is configured to detect the frequency of vibration at least in part on detecting a response in the reflection of the signals at an offset from a frequency of the microwave carrier signal.

6. The apparatus of claim 1, wherein the detection circuit is configured to determine at least one of a type of the object or a distance of the object from the detection circuit.

7. The apparatus of claim 6, wherein the detection circuit comprises an array of elements in different positions configured to transmit the signals, the detection circuit configured to determine at least one of the type of the object or the distance of the object based on the reflection of the signals received by the elements in the array.

8. The apparatus of claim 1, further comprising a second circuit configured to generate a magnetic pulse in response to detecting the object is a metal object based on the frequency of vibration, the magnetic pulse having a magnetic field strength higher than the magnetic field strength of the magnetic field.

9. The apparatus of claim 8, wherein the detection circuit is configured detect a characteristic depending on movement of the object in response to the magnetic pulse to confirm the presence of the metal object.

10. The apparatus of claim 9, wherein the characteristic comprises a velocity of the object as it moves in response to the magnetic pulse.

11. The apparatus of claim 1, wherein the load comprises a battery of an electric vehicle.

18. The method of claim 11, further comprising generating a magnetic pulse in response to detecting the object is a metal object based on the frequency of vibration, the magnetic pulse having a magnetic field strength higher than the magnetic field strength of the magnetic field.

19. The method of claim 18, further comprising detecting a characteristic depending on movement of the object in response to the magnetic pulse to confirm the presence of the metal object.

20. The method of claim 19, wherein the characteristic comprises a velocity of the object as it moves in response to the magnetic pulse.

12. A method for detecting a presence of an object in a magnetic field, the method comprising:

generating the magnetic field and transferring power wirelessly at a level sufficient to power or charge a load via the magnetic field; and

transmitting signals and detecting, based on a reflection of the transmitted signals, a frequency of vibration of the object caused by the magnetic field.

13. The method of claim 12, wherein generating the magnetic field comprises applying an alternating current to an antenna at a frequency, and wherein detecting comprises detecting that the object is a metal object based on the frequency of vibration.

14. The method of claim 13, wherein detecting comprises detecting that the object is a metal object in response to the detecting that the frequency of vibration is substantially twice the frequency of the alternating current.

15. The method of claim 12, wherein the signal comprises a microwave carrier signal and wherein detecting comprises detecting the frequency of vibration based on a micro-Doppler effect.

16. The method of claim 15, wherein detecting comprises detecting the frequency of vibration at least in part on detecting a response in the reflection of the signals at an offset from a frequency of the microwave carrier signal.

17. The method of claim 12, wherein transmitting signals comprises transmitting signals from each of an array of elements in different positions, wherein the method further comprises determining at least one of a type of the object or a distance of the object based on the reflection of the signals received by the elements in the array.

21. An apparatus for detecting a presence of an object in a magnetic field, the apparatus comprising:

means for generating the magnetic field and transferring power wirelessly at a level sufficient to power or charge a load via the magnetic field; and

means for transmitting signals and means for detecting, based on a reflection of the transmitted signals, a frequency of vibration of the object caused by the magnetic field.

22. The apparatus of claim 21, wherein the means for generating the magnetic field comprises means for generating the magnetic field at a frequency, and wherein the means for detecting comprises means for detecting that the object is a metal object based on the frequency of vibration.

23. The apparatus of claim 22, wherein the means for detecting comprises means for detecting that the object is a metal object in response to the detecting that the frequency of vibration is substantially twice the frequency of the magnetic field.

24. The apparatus of claim 21, wherein the signal comprises a microwave carrier signal and wherein the means for detecting comprises means for detecting the frequency of vibration based on a micro-Doppler effect.

25. The apparatus of claim 24, wherein the means for detecting comprises means for detecting the frequency of vibration at least in part on detecting a response in the reflection of the signals at an offset from a frequency of the microwave carrier signal.

26. The apparatus of claim 21, wherein the means for transmitting signals comprises means for transmitting signals from each of an array of elements in different positions, wherein the apparatus further comprises means for determining at least one of a type of the object or a distance of the object based on the reflection of the signals received by the elements in the array.

27. The apparatus of claim 21, further comprising means for generating a magnetic pulse in response to detecting the object is a metal object based on the frequency of vibration, the magnetic pulse having a magnetic field strength higher than the magnetic field strength of the magnetic field.

28. The apparatus of claim 27, further comprising means for detecting a characteristic depending on movement of the object in response to the magnetic pulse to confirm the presence of the metal object.

29. The apparatus of claim 28, wherein the characteristic comprises a velocity of the object as it moves in response to the magnetic pulse.