EP-4742498-A1 - AN APPARATUS

EP4742498A1EP 4742498 A1EP4742498 A1EP 4742498A1EP-4742498-A1

Abstract

An apparatus comprising a power-emitting device comprising an antenna, power circuitry configured to provide power via the antenna for wireless charging of a power-receiving device, and a processor, the processor configured to at least analyse signals from said antenna to determine the presence of the power-receiving device proximal the power-emitting device and to determine the presence of a foreign object, FO, proximal the power-emitting device. Wherein the processor is configured to control the power circuitry to either interrupt or not initiate said provision of power for wireless charging of the power-receiving device based on said analysis of on one or both of said analysis of the signals and the power provided by the power circuitry being indicative of the power-emitting device being proximal to a foreign object. In response to said analysis of the signals being indicative that a FO-removal event has occurred, the processor is configured to control the power circuitry to provide power for wireless charging of the power-receiving device.

Inventors

VERMA, CHETAN
WOBAK, MARKUS

Assignees

NXP B.V.

Dates

Publication Date: 20260513
Application Date: 20241107

Claims (15)

An apparatus comprising: a power-emitting device comprising: an antenna, power circuitry configured to provide power via the antenna for wireless charging of a power-receiving device, and a processor, the processor configured to at least analyse signals from said antenna to determine the presence of the power-receiving device proximal the power-emitting device and to determine the presence of a foreign object, FO, proximal the power-emitting device, and wherein the processor is configured to: based on one or both of said analysis of the signals and the power provided by the power circuitry being indicative of the power-emitting device being proximal to a foreign object, control the power circuitry to either interrupt or not initiate said provision of power for wireless charging of the power-receiving device, and in response to said analysis of the signals being indicative that a FO-removal event has occurred, wherein said FO-removal event comprises the FO no longer being proximal the power-emitting device while the power-receiving device remains proximal the power-emitting device, control the power circuitry to provide power for wireless charging of the power-receiving device.
The apparatus according to claim 1, wherein said analysis of the signals being indicative of the power-emitting device being proximal to the foreign object is determined by the processor being configured to one or both of: determine a decrease in an efficiency of power transfer between the power-emitting device and the power-receiving device, based on information indicative of the power received by the power-receiving device in the signals from said antenna and information indicative of the power provided by the power circuitry; and determine a rate of change, above a threshold, in the power provided by the power circuitry for wireless charging of the power-receiving device.
The apparatus according to claim 1 or claim 2, wherein the processor is configured to, based on said analysis of the signals being indicative that the power-emitting device is proximal to the power-receiving device and no FO is proximal the power-receiving device, control the power circuitry to provide power for wireless charging of the power-receiving device.
The apparatus according to claim 1 or claim 2, wherein the processor being configured to control the power circuitry to either interrupt or not initiate said provision of power for wireless charging of the power-receiving device comprises the processor being configured such that: if said analysis of the signals is indicative of the power-emitting device being proximal to the FO at a time when the power circuitry is providing power for wireless charging of the power-receiving device, said processor is configured to control the power circuitry to interrupt said provision of power for wireless charging of the power-receiving device; and if said analysis of the signals is indicative of the power-emitting device being proximal to the FO and at later time the power-receiving device is determined to be proximal to the power-emitting device in addition to said FO, said processor is configured to control the power circuitry to not initiate said provision of power for wireless charging of the power-receiving device at least while said FO is determined to be proximal the power-emitting device.
The apparatus of any preceding claim, wherein said processor is configured to, as part of said analysis of the signals being indicative that the FO-removal event has occurred, compare one or more signals received from the antenna to a predetermined signature that characterises signals expected from said antenna without the foreign object proximal the power-emitting device but with the power-receiving device proximal the power-emitting device, and determine the FO-removal event based on said comparison.
The apparatus of claim 5, wherein the apparatus includes antenna loading measurement circuitry configured to measure an antenna voltage from the antenna in response to a current provided to the antenna, and wherein said comparison comprises a comparison of the antenna voltage to the predetermined signature, wherein said predetermined signature comprises at least one antenna voltage characterising when the foreign object is not proximal the power-emitting device but the power-receiving device is proximal the power-emitting device.
The apparatus of claim 6, wherein said predetermined signature comprises a range of antenna voltages characterising when the foreign object is not proximal the power-emitting device but the power-receiving device is proximal the power-emitting device.
The apparatus of claim 5, wherein the apparatus includes antenna loading measurement circuitry configured to measure an antenna voltage from the antenna in response to a current provided to the antenna, wherein the antenna loading measurement circuitry is configured to determine an in-phase, I, component and a quadrature, Q, component of the antenna voltage, and wherein said comparison comprises a comparison of the I and Q components of the antenna voltage to the predetermined signature, and wherein said predetermined signature is based on I and Q components characterising when the foreign object is not proximal the power-emitting device but the power-receiving device is proximal the power-emitting device.
The apparatus of claim 8, wherein said processor is configured to determine that the FO-removal event has occurred based on the condition that: the I component and the Q component of the antenna voltage is within a threshold tolerance of the I and Q components of the predetermined signature following the control of the power circuitry to interrupt said provision of power for wireless charging of the power-receiving device.
The apparatus of any one of claims 5 to 9, wherein the processor is configured to determine the predetermined signature based on one or more measurements of the respective antenna voltages at a time when said analysis of the signals is indicative of the power-emitting device being proximal to the power-receiving device while not being indicative that a foreign-object is proximal the power-emitting device.
The apparatus of claim 9, wherein the processor is configured to store a plurality of predetermined signatures and said comparison is a comparison to determine whether the I and Q components of the antenna voltage match with any one of said plurality of predetermined signatures.
The apparatus of claim 11, wherein the processor is configured to store, in a memory, the plurality of predetermined signatures each with a confidence score, wherein based on the antenna voltage matching with any one of said plurality of predetermined signatures, the processor is configured establish communication between the power-emitting device and the power-receiving device, wherein upon unsuccessfully establishing said communication, the processor is configured to decrease the confidence score of the respective signature of the plurality of predetermined signatures, and wherein the confidence score is used to determine whether to retain or remove the respective signature of the plurality of predetermined signatures from the memory.
The apparatus of any preceding claim wherein the processor is configured to perform said analysis of the signals from said antenna to determine the presence of the foreign object proximal the power-emitting device by the processor being configured to provide for transmission of one or more messages for the power-receiving device and to receive one or more response messages during a time when the power circuitry is providing power for wireless charging, wherein the processor is configured to extract from the one or more response messages, information indicative of the power the power-receiving device is receiving and determine changes in said power the power-receiving device is receiving relative to the power the power circuitry is providing.
The apparatus of any preceding claim wherein the processor being configured to analyse the signals from said antenna to determine the presence of the power-receiving device proximal the power-emitting device and to determine the presence of a foreign object proximal the power-emitting device is provided by the processor being configured to measure changes in impedance of the antenna and compare said changes to predetermined information.
A method of controlling an apparatus, the apparatus comprising a power-emitting device, the power-emitting device comprising: an antenna; power circuitry configured to provide power via the antenna for wireless charging of a power-receiving device; and a processor, wherein the method comprises, by the processor, analysing at least signals from said antenna to determine the presence of the power-receiving device proximal the power-emitting device and to determine the presence of a foreign object proximal the power-emitting device, and based on one or both of said analysis of the signals and the power provided by the power circuitry being indicative of the power-emitting device being proximal to a foreign object, FO, controlling the power circuitry to either interrupt or not initiate said provision of power for wireless charging of the power-receiving device, and in response to said analysis of the signals being indicative that a FO-removal event has occurred, wherein said FO-removal event comprises the FO no longer being proximal the power-emitting device while the power-receiving device remains proximal the power-emitting device, controlling the power circuitry to provide power for wireless charging of the power-receiving device.

Description

Field The present disclosure relates to an apparatus, and in particular, an apparatus comprising a power-emitting device, an antenna and power circuitry. It also relates to a method for controlling said apparatus. Background Wireless charging of accessories can be convenient for the user. Near Field Communication (NFC) can be used to perform wireless charging (WLC) of small-scale battery-powered accessories. During an ongoing charging activity, a power-emitting device performs regular presence checks for power-receiving devices and foreign objects (FO, i.e. metal or other NFC tags) in close proximity to the power-emitting device. Typically, in the case of FO presence detection, the power-emitting device stops an ongoing charging activity due to safety risks (like overheating) or to avoid damage to the FO (like overexposure of too high magnetic field strength). Summary According to a first aspect of the present disclosure there is provided an apparatus comprising: a power-emitting device comprising: an antenna,power circuitry configured to provide power via the antenna for wireless charging of a power-receiving device, anda processor, the processor configured to at least analyse signals from said antenna to determine the presence of the power-receiving device proximal the power-emitting device and to determine the presence of a foreign object, FO, proximal the power-emitting device, andwherein the processor is configured to: based on one or both of said analysis of the signals and the power provided by the power circuitry being indicative of the power-emitting device being proximal to a foreign object, control the power circuitry to either interrupt or not initiate said provision of power for wireless charging of the power-receiving device, andin response to said analysis of the signals being indicative that a FO-removal event has occurred, wherein said FO-removal event comprises the FO no longer being proximal the power-emitting device while the power-receiving device remains proximal the power-emitting device, control the power circuitry to provide power for wireless charging of the power-receiving device. In one or more embodiments said analysis of the signals being indicative of the power-emitting device being proximal to a foreign object is determined by the processor being configured to one or both of: determine a decrease in efficiency of power transfer between the power-emitting device and the power-receiving device, based on information indicative of the power received by the power-receiving device in the signals from said antenna and information indicative of the power provided by the power circuitry; anddetermine a rate of change, above a threshold, in the power provided by the power circuitry for wireless charging of the power-receiving device. In one or more embodiments the processor is configured to, based on said analysis of the signals being indicative that the power-emitting device is proximal to the power-receiving device and no FO is proximal the power-receiving device, control the power circuitry to provide power for wireless charging of the power-receiving device. In one or more embodiments the processor being configured to control the power circuitry to either interrupt or not initiate said provision of power for wireless charging of the power-receiving device comprises the processor being configured such that: if said analysis of the signals is indicative of the power-emitting device being proximal to the FO at a time when the power circuitry is providing power for wireless charging of the power-receiving device, said processor is configured to control the power circuitry to interrupt said provision of power for wireless charging of the power-receiving device; andif said analysis of the signals is indicative of the power-emitting device being proximal to the FO and at later time the power-receiving device is determined to be proximal to the power-emitting device in addition to said FO, said processor is configured to control the power circuitry to not initiate said provision of power for wireless charging of the power-receiving device at least while said FO is determined to be proximal the power-emitting device. In one or more embodiments said processor is configured to, as part of said analysis of the signals being indicative that the FO-removal event has occurred, compare one or more signals received from the antenna to a predetermined signature that characterises signals expected from said antenna without the foreign object proximal the power-emitting device but with the power-receiving device proximal the power-emitting device, and determine the FO-removal event based on said comparison. In one or more embodiments the apparatus includes antenna loading measurement circuitry configured to measure an antenna voltage from the antenna in response to a current provided to the antenna, and wherein said comparison comprises a comparison of the antenna voltage to the predetermined signatur