Detection apparatus, power supply system, and method of controlling detection apparatus

• US 9,892,848 B2
• Filed: 04/23/2014
• Issued: 02/13/2018
• Est. Priority Date: 05/16/2013
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Omae, Uichiro, Kiyakawauchi, Tamotsu
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Perez Borroto, Alfonso
• Application Number:
  US14/259,358
• Publication Number:
  US 20140339908A1
• Time in Patent Office: 1,392 Days
• Field of Search: 307104
• 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 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• 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 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A detection apparatus includes: a measurement coil disposed in a vicinity of a power reception coil configured to receive power supplied through a magnetic field; a measurement section configured to measure a voltage of the measurement coil as a measurement coil voltage; and a foreign object detection section configured to obtain an electrical characteristic value of at least one of the power reception coil and the measurement coil on the basis of the measurement coil voltage, and to detect a foreign object in the magnetic field if the electrical characteristic value is lower than a predetermined lower limit threshold value.

Claims

1. A detection apparatus comprising:

a measurement coil disposed in a vicinity of a power reception coil configured to receive power supplied through a magnetic field;

a measurement section configured to measure a measurement coil voltage of the measurement coil; and

a foreign object detection section configured to

obtain an electrical characteristic value of at least one of the power reception coil and the measurement coil on a basis of the measurement coil voltage,

determine whether the electrical characteristic value is lower than a predetermined lower limit threshold value, and

responsive to determining that the electrical characteristic value is lower than the predetermined lower limit threshold value, output a signal that is indicative of a detection of a foreign object to a power reception control circuit of a power reception apparatus,

wherein the power reception control circuit is configured to control a load connection circuit to disconnect a battery based on the signal that is indicative of the detection of the foreign object.

2. The detection apparatus according to claim 1,

wherein the foreign object detection section is further configured to

determine whether the electrical characteristic value is higher than an upper limit threshold value greater than the predetermined lower limit threshold value, and

responsive to determining that the electrical characteristic value is higher than the upper limit threshold value, output the signal that is indicative of the detection of the foreign object to the power reception control circuit.

3. The detection apparatus according to claim 2,

wherein the upper limit threshold value is higher than a reference value being the electrical characteristic value when there is a lack of the foreign object, and the predetermined lower limit threshold value is a lower value than the reference value.

4. The detection apparatus according to claim 1,

wherein the measurement section is configured to further measure a voltage and a current of the power reception coil, and

the foreign object detection section is configured to obtain impedance of the power reception coil from the measurement coil voltage, and the voltage and the current of the power reception coil as the electrical characteristic value.

5. The detection apparatus according to claim 1,

wherein the measurement section is configured to further measure a voltage of the power reception coil as a power reception coil voltage, and

the foreign object detection section is configured to obtain a voltage ratio of the measurement coil voltage and the power reception coil voltage as the electrical characteristic value.

6. The detection apparatus according to claim 5,

the power reception coil is configured to receive a first power and a second power having a different amount of power with each other in sequence, and

the foreign object detection section is configured to obtain, as the electrical characteristic value, a difference between the voltage ratio obtained when the first power is received, and the voltage ratio obtained when the second power is received.

7. The detection apparatus according to claim 1,

wherein the measurement coil is configured to have a smaller coil surface area than that of the power reception coil.

8. The detection apparatus according to claim 7,

wherein the measurement coil is disposed inside the power reception coil.

9. The detection apparatus according to claim 1,

wherein the measurement coil is disposed on a substantially same plane as that of the power reception coil.

10. The detection apparatus according to claim 1,

wherein the measurement coil is disposed at a position where a coil surface of the measurement coil and that of the power reception coil have a substantially same center position.

11. The detection apparatus according to claim 1,

wherein the power is power supplied from a power supply apparatus, and

the detection apparatus further comprising a transmission section configured to transmit a control signal requesting a decrease in an amount of the power if the foreign object is detected.

15. The detection apparatus according to claim 1,

wherein the measurement coil and the power reception coil are used in combination with each other.

16. The detection apparatus according to claim 1,

wherein the measurement coil comprises a first one or more coils, and wherein the power reception coil comprises a second one or more coils.

12. A detection apparatus comprising:

a measurement coil disposed in a vicinity of a power supply coil of a power supply apparatus and disposed external to a power reception apparatus including a power reception coil, the power supply coil configured to supply power through a magnetic field to the power reception coil;

a measurement section configured to measure a measurement coil voltage of the measurement coil; and

a foreign object detection section configured to

obtain an electrical characteristic value of at least one of the power supply coil and the measurement coil on a basis of the measurement coil voltage,

determine whether the electrical characteristic value is lower than a predetermined lower limit threshold value, and

responsive to determining that the electrical characteristic value is lower than the predetermined lower limit threshold value, output a signal that is indicative of a detection of a foreign object to a power supply control section of the power supply apparatus.

17. The detection apparatus according to claim 12,

wherein the foreign object detection section is further configured to

determine whether the electrical characteristic value is higher than an upper limit threshold value greater than the predetermined lower limit threshold value, and

responsive to determining that the electrical characteristic value is higher than the upper limit threshold value, output the signal that is indicative of the detection of the foreign object to the power supply control section of the power supply apparatus.

18. The detection apparatus according to claim 17,

wherein the upper limit threshold value is higher than a reference value being the electrical characteristic value when there is a lack of the foreign object, and the predetermined lower limit threshold value is a lower value than the reference value.

19. The detection apparatus according to claim 12,

wherein the measurement coil and the power supply coil are used in combination with each other.

20. The detection apparatus according to claim 12,

wherein the measurement coil comprises a first one or more coils, and wherein the power supply coil comprises a second one or more coils.

13. A power supply system comprising:

a power reception apparatus including a power reception coil configured to receive power through a magnetic field; and

a power supply apparatus including

a power supply coil configured to supply the power through the magnetic field,

a power supply control circuit configured to control the power supply coil,

a measurement coil disposed in a vicinity of the power supply coil,

a measurement section configured to measure a measurement coil voltage of the measurement coil, and

a foreign object detection section configured to

obtain an electrical characteristic value of at least one of the power supply coil and the measurement coil on a basis of the measurement coil voltage,

determine whether the electrical characteristic value is lower than a predetermined lower limit threshold value, and

responsive to determining that the electrical characteristic value is lower than the predetermined lower limit threshold value, output a signal that is indicative of a detection of a foreign object to the power supply control circuit.

21. The power supply system according to claim 13,

wherein the foreign object detection section is further configured to

determine whether the electrical characteristic value is higher than an upper limit threshold value greater than the predetermined lower limit threshold value, and

responsive to determining that the electrical characteristic value is higher than the upper limit threshold value, output the signal that is indicative of the detection of the foreign object to the power supply control circuit.

22. The power supply system according to claim 21,

wherein the upper limit threshold value is higher than a reference value being the electrical characteristic value when there is a lack of the foreign object, and the predetermined lower limit threshold value is a lower value than the reference value.

23. The power supply system according to claim 13,

wherein the measurement coil and the power supply coil are used in combination with each other.

24. The power supply system according to claim 13,

wherein the measurement coil comprises a first one or more coils, and wherein the power supply coil comprises a second one or more coils.

14. A method of controlling a detection apparatus, the method comprising:

measuring, by a measurement section of a power supply apparatus, a measurement coil voltage of a measurement coil disposed in a vicinity of a power supply coil configured to supply power supplied through a magnetic field;

obtaining, by a foreign object detection section of the power supply apparatus, an electrical characteristic value of at least one of the power supply coil and the measurement coil on a basis of the measurement coil voltage;

determining, by the foreign object detection section, whether the electrical characteristic value is lower than a predetermined lower limit threshold value; and

outputting, by the foreign object detection section, a signal that is indicative of a detection of a foreign object to a power supply control circuit of the power supply apparatus in response to determining that the electrical characteristic value is lower than the predetermined lower limit threshold value.

25. The method according to claim 14, further comprising:

determining whether the electrical characteristic value is higher than an upper limit threshold value greater than the predetermined lower limit threshold value, and

outputting the signal that is indicative of the detection of the foreign object to the power supply control circuit in response to determining that the electrical characteristic value is higher than the upper limit threshold value.

26. The method according to claim 14, further comprising:

measuring, by the measurement section, a voltage and a current of the power supply coil, and wherein obtaining the electrical characteristic value further includes obtaining an impedance of the power supply coil from the measurement coil voltage and from the voltage and the current of the power supply coil.