Adaptive wireless power transfer system

• US 10,164,469 B1
• Filed: 09/14/2016
• Issued: 12/25/2018
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Jadidian, Jouya, Cabral, Steven W., Pathak, Vaneet
• Primary Examiner(s): Deberadinis, Robert
• Application Number:
  US15/265,061
• Time in Patent Office: 832 Days
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment

Abstract

Wireless power may be transferred using wireless power elements such as coil antennas for inductive wireless power transfer technology or patch antennas for capacitive wireless power transfer technology. These antennas in source equipment may couple in a near-field region to antennas implemented in target equipment. Wireless power may also be transferred from the source equipment to the target equipment using radiating antennas in their far-field regions. Wireless power transfer may be optimized by performing channel estimation operations. Foreign objects can be detected and located using sensors or by analyzing the quality of wireless channels. Optimum power transfer settings may be used to maximize wireless power transfer to a set of the antennas in the target equipment while minimizing power transfer to the foreign object.

Claims

1. A system in which power is transferred wirelessly in the vicinity of a foreign object, comprising:

source equipment having an array of source wireless power transfer elements and having source wireless power transfer circuitry; and

target equipment having an array of target wireless power transfer elements and having target wireless power transfer circuitry, wherein the source equipment and target equipment are configured to transfer power wirelessly from the source equipment to the target equipment using the array of source wireless power transfer elements, the source wireless power transfer circuitry, the array of target wireless power transfer elements, and the target wireless power transfer circuitry while aligning a wireless power null with the foreign object by using at least one of the target wireless power transfer elements to transmit wireless power signals while the source wireless power transfer elements are transmitting wireless power signals.

2. The system defined in claim 1 further comprising:

at least one sensor, wherein the source equipment and target equipment is configured to use the sensor to locate the foreign object.

3. The system defined in claim 2 wherein the source equipment and target equipment are configured to transfer the power wirelessly from the source equipment to the target equipment using the array of source wireless power transfer elements, the source wireless power transfer circuitry, the array of target wireless power transfer elements, and the target wireless power transfer circuitry based at least partly on information from the sensor.

4. The system defined in claim 3 wherein the source equipment and target equipment are configured to transfer the power wirelessly from the source equipment to the target equipment based at least partly on channel estimates performed using the source and target wireless power transfer circuitry and the source and target arrays of wireless power transfer elements.

5. The system defined in claim 3 wherein the array of source wireless power transfer elements comprises an array of source coils, wherein the array of target wireless power transfer elements comprises an array of target coils, and wherein the source and target equipment are configured to transfer power wirelessly to the target equipment from the source equipment by directing wireless power towards a subset of target coils in the target equipment and away from the foreign object.

6. A method of transferring power wirelessly from source equipment having wireless power transfer circuitry and having an array of coils to at least one target coil in target equipment, comprising:

performing channel estimation operations using the array of coils and the at least one target coil in the target equipment;

determining wireless power transfer settings to use in transmitting signals with the array of coils using the wireless power transfer circuitry based at least partly on the channel estimation operations; and

transmitting wireless power signals from the array of coils to the at least one target coil in the target equipment that is near-field coupled to the array of coils using the wireless power transfer settings, wherein performing the channel estimation operations using the array of coils and the at least one target coil in the target equipment comprises measuring a reflected impedance from the at least one target coil in the target equipment at each of the coils in the array of coils.

7. The method defined in claim 6 wherein performing the channel estimation operations using the array of coils and the at least one target coil in the target equipment comprises receiving signals at each of the coils in the array of coils with the wireless power transfer circuitry while transmitting signals from transmitter circuitry coupled to the at least one target coil in the target equipment.

8. The method defined in claim 7 wherein the at least one target coil in the target equipment comprises an array of target coils and wherein transmitting the wireless power signals comprises transmitting the wireless power signals from the array of coils in the source equipment to the array of target coils in the target equipment.

9. The method defined in claim 8 further comprising transmitting signals from at least one of the target coils in the array of target coils in the target equipment while transmitting the wireless power signals from the array of coils in the source equipment to the array of target coils in the target equipment.

10. The method defined in claim 9 further comprising:

determining the location of a foreign object, wherein transmitting the wireless power signals from the array of coils comprises transmitting the wireless power signals from the array of coils based at least partly on the location of the foreign object.

11. The method defined in claim 10 wherein the source equipment includes at least one sensor and control circuitry and wherein determining the location of the foreign object comprises:

using the control circuitry and the sensor to determine the location of the foreign object.

12. A method of transferring power wirelessly from source equipment having wireless power transfer circuitry and having an array of coils to at least one target coil in target equipment, comprising:

performing channel estimation operations using the array of coils and the at least one target coil in the target equipment;

determining wireless power transfer settings to use in transmitting signals with the array of coils using the wireless power transfer circuitry based at least partly on the channel estimation operations;

transmitting wireless power signals from the array of coils to the at least one target coil in the target equipment that is near-field coupled to the array of coils using the wireless power transfer settings; and

determining where a foreign object od located using the source equipment, wherein transmitting the wireless power signals from the array of coils comprises transmitting the wireless power signals from the array of coils based at least partly on where the foreign object is located.

13. A method of transferring power wirelessly from source equipment having wireless power transfer circuitry and having an array of coils to at least one target coil in target equipment, comprising:

performing channel estimation operations using the array of coils and the at least one target coil in the target equipment;

determining wireless power transfer settings to use in transmitting signals with the array of coils using the wireless power transfer circuitry based at least partly on the channel estimation operations; and

transmitting wireless power signals from the array of coils to the at least one target coil in the target equipment that is near-field coupled to the array of coils using the wireless power transfer settings, wherein the target equipment comprises a vehicle and wherein transmitting the wireless power signals comprises transmitting the wireless power signals to the target coil in the vehicle.

14. A system for wirelessly transmitting power from a wireless power unit to a vehicle having at least one target antenna, comprising:

an array of antennas that are near-field coupled to the at least one target antenna;

at least one sensor configured to detect foreign objects; and

wireless power transfer circuitry configured to transfer power wirelessly to the target antenna using the array of antennas based at least partly on information from the sensor about the foreign object.

15. The system defined in claim 14 wherein the array of antennas comprises an array of coils.

16. The system defined in claim 15 further comprising control circuitry configured to use the information from the sensor to determine where the foreign object is located, wherein the control circuitry is configured to halt wireless power transfer with the wireless power transfer circuitry based at least partly on the information.

17. The system defined in claim 14 wherein the at least one target antenna comprises one of an array of target antennas, wherein the system further comprises a transmitter coupled to a given one of the target antennas in the array of target antennas, and wherein the transmitter transmits signals through the given one of the target antennas while the wireless power transfer circuitry transfers power wirelessly to the vehicle.

18. The system defined in claim 17 wherein the transmitter is configured to transmit signals through the given one of the target antennas in the array of target antennas while the wireless power transfer circuitry transfers power wirelessly to the vehicle based at least partly on where the foreign object is located.

19. The system defined in claim 14 further comprising control circuitry configured to perform channel estimation operations using the array of antennas and the at least one target antenna in the vehicle.