Method for detecting an object to be charged and associated charging device
A method for detecting an object to be charged by an induction-charging device including at least one transmitting coil. The method includes transmission, by the at least one coil, of an electrical pulse the value of which is within a window of values predetermined using test receivers, and the object to be charged generating a communication signal in response. The method including, if charging conditions are favorable, the modulation of the value of the electrical pulse outside of the window of predetermined values according to the presence and/or the value of the communication signal, in order to detect the presence of an object to be charged.
1 . A method for detecting an object to be charged by an induction-charging device comprising at least one transmitting coil, the method comprising:
transmitting, by the at least one coil, an analog signal to detect whether charging conditions are favorable;
transmitting, by the at least one coil, an electrical pulse the value of which is within a window of values predetermined using test receivers in a certification phase of the Wireless Power Consortium (WPC) standard to the object to be charged; and
if charging conditions are favorable,
in the absence of a communication signal modulating the value of the electrical pulse outside of the window of predetermined values of the WPC standard in order to detect the presence of the object to be charged, wherein the modulated electrical pulse has a voltage higher than an upper limit of the window of predetermined values of the WPC standard, and
when a communication signal is received by the at least one coil at a maximum value, modulating the value of the electrical pulse outside of the window of predetermined values of the WPC standard in order to detect the presence of the object to be charged, wherein the modulated electrical pulse has a voltage lower than a lower limit of the window of predetermined values of the WPC standard.
2 . The method for detecting an object to be charged by a charging device as claimed in claim 1 , comprising at least one transmitting coil, the method further comprising the following steps for each coil:
a) detecting the presence of an object on a charging surface of said device;
b) checking charging conditions;
c) if the charging conditions are favorable:
i) transmitting, to the object, an electrical pulse the value of which is within a window of values predetermined beforehand using test receivers in a certification phase;
ii) if the object transmits a communication signal lower than a maximum value in response, then an object to be charged is detected, otherwise:
iii) in the absence of a communication signal, or a communication signal of maximum value, then transmitting, to the object, a modified electrical pulse the value of which is located outside of the window of predetermined values:
a. if the object transmits a communication signal in response, then an object to be charged is detected;
b. otherwise a parasitic object is detected.
3 . The detection method as claimed in claim 1 , wherein if the charging conditions are unfavorable, then the electrical pulse has a voltage lower than a lower limit predetermined beforehand using test receivers in a certification phase.
4 . The detection method as claimed in claim 1 , wherein when the charging conditions are unfavorable for a coil, terminating transmission of the electrical pulse by the at least one coil.
5 . The detection method as claimed in claim 1 , wherein, the charging device comprises a plurality of transmitting coils, the method is repeated for each coil.
6 . The detection method as claimed in claim 5 , wherein when modulating the value of the electrical pulse based on the absence of a communication signal, modulating the value of the electrical pulse transmitted from each of the plurality of transmitting coils at a voltage higher than the upper limit of the window of predetermined values of the WPC standard, wherein the voltage for each transmitting coil is proportional to a different percentage value from the higher limit for each of the plurality of transmitting coils.
7 . The detection method as claimed in claim 5 , wherein when modulating the value of the electrical pulse based on receiving a communication signal at a maximum value, modulating the value of the electrical pulse transmitted from each of the plurality of transmitting coils at a voltage lower than the lower limit of the window of predetermined values of the WPC standard, wherein the voltage for each transmitting coil is proportional to a different percentage value from the lower limit for each of the plurality of transmitting coils.
8 . The detection method as claimed in claim 1 , further comprising a prior step of calibrating the voltage values of the modified electrical pulse outside of the window of predetermined values according to various types of objects to be charged.
9 . The detection method as claimed in claim 1 , wherein the checking of favorable charging conditions comprises measuring at least one parameter of the at least one transmitting coil and comparing said measurement with predetermined threshold values of the same parameter, obtained beforehand for various types of objects to be charged.
10 . The detection method as claimed in claim 9 , wherein the parameter is a quality factor, and/or a variation in resistance and/or a variation in inductance, and/or a variation in a resonant frequency of the transmitting coil.
11 . A non-transitory computer program product comprising program code instructions for carrying out the steps of the detection method as claimed in claim 1 , when said program is executed on a computer.
12 . A device for charging an object, comprising at least one transmitting coil, the device comprising:
a) means for detecting an object on the charging surface;
and, for each coil:
b) means for checking charging conditions based on transmitting an analog signal to detect whether charging conditions are favorable;
c) means for detecting the reception of a communication signal and for comparing the value of said received communication signal with a maximum value; and
d) means for modulating a value of an electrical pulse transmitted by the at least one coil, outside of a window of values predetermined beforehand using test receivers in a certification phase of the of the Wireless Power Consortium (WPC) standard, according to the result of said check and according to the presence and/or the value of the communication signal, wherein in an absence of a communication signal, the value of the electrical pulse is modulated outside of the window of predetermined values of the WPC standard in order to detect the presence of the object to be charged, wherein the modulated electrical pulse has a voltage higher than an upper limit of the window of predetermined values of the WPC standard, and when a communication signal is received by the at least one coil at a maximum value, modulating the value of the electrical pulse outside of the window of predetermined values of the WPC standard in order to detect the presence of the object to be charged, wherein the modulated electrical pulse has a voltage lower than a lower limit of the window of predetermined values of the WPC standard.
13 . The device for charging an object as claimed in claim 12 , wherein the checking means comprise means for measuring at least one parameter of the transmitting coil and means for comparing the measurement with predetermined threshold values of the same parameter, obtained beforehand for various types of objects to be charged.
14 . The charging device as claimed in claim 13 , wherein the parameter is a quality factor, and/or a variation in resistance and/or a variation in inductance, and/or a variation in a resonant frequency of the transmitting coil.
15 . A motor vehicle comprising a charging device as claimed in claim 12 .
16 . The device for charging an object as claimed in claim 12 , wherein when modulating the value of the electrical pulse based on the absence of a communication signal, modulating the value of the electrical pulse transmitted from each coil at a voltage higher than the upper limit of the window of predetermined values of the WPC standard, wherein the voltage for each coil is proportional to a different percentage value from the higher limit for each of the coils.
17 . The device for charging an object as claimed in claim 12 , wherein when modulating the value of the electrical pulse based on receiving a communication signal at a maximum value, modulating the value of the electrical pulse transmitted from each coil at a voltage lower than the lower limit of the window of predetermined values of the WPC standard, wherein the voltage for each coil is proportional to a different percentage value from the lower limit for each of the coils.