Power supply device, power receiving device, charging system, and obstacle detection method
View Patent ↗Provided are a power supply device, a power receiving device, a charging system, and an obstacle detection method that obtain a sufficient obstacle detection sensitivity even when an obstacle is small. A modulation unit ( 202 ) performs amplitude modulation or phase modulation on a test data sequence output from a test data sequence storage unit ( 201 ). A power control unit ( 203 ) generates, according to an instruction from a determination unit ( 204 ), a power control signal for increasing the power level of the test data sequence every time when the test data sequence is transmitted. The determination unit ( 204 ) determines whether there is an obstacle between the power receiving device and the power supply device based on whether the test data sequence output from the test data sequence storage unit ( 201 ) coincides with the test data sequence output from a power-transmitting-side receiving circuit ( 124 ).
1. An electric supply apparatus that supplies electric power in a contactless manner to an electric reception apparatus provided in a vehicle, using electromagnetic induction, the electric supply apparatus comprising:
a transmitting section that transmits a first test data string having a predetermined data sequence to the electric reception apparatus using the electromagnetic induction in a coil;
a control section that controls the transmitting section to transmit the first test data string from the transmitting section;
a receiving section that receives a data string transmitted from the electric reception apparatus as a second test data string obtained by the electric reception apparatus via demodulation of the first test data string received by the electric reception apparatus; and
a determination section that determines whether there is an obstacle between the electric reception apparatus and the electric supply apparatus based on whether the first test data string transmitted by the transmitting section coincides with the second test data string received by the receiving section.
2. The electric supply apparatus according to claim 1 , wherein:
the control section controls the transmitting section to repeatedly transmit the first test data string from the transmitting section while increasing a transmission electric power level; and
the determination section determines whether there is an obstacle between the electric reception apparatus and the electric supply apparatus based on a transmission electric power level used for transmission of the first test data string from the transmitting section when the first test data string transmitted by the transmitting section coincides with the second test data string received by the receiving section.
3. The electric supply apparatus according to claim 1 , wherein:
the determination section determines that there is no obstacle when a transmission electric power level of the first test data string of a case where the first test data string transmitted from the transmitting section coincides with the second test data string received by the receiving section is equal to a transmission electric power level that is previously measured when the first test data string and the second test data string coincide with each other in a state where there is no obstacle; and the determination section determines that there is an obstacle when the transmission electric power level exceeds the transmission electric power level that is previously measured when the first test data string and the second test data string coincide with each other in a state where there is no obstacle.
4. The electric supply apparatus according to claim 1 , further comprising a modulation section that amplitude-modulates or phase-modulates the first test data string.
5. The electric supply apparatus according to claim 1 , wherein the first test data string includes a plurality of data sequences associated with the respective transmission electric power levels variable in a stepwise manner.
6. An electric reception apparatus that is provided in a vehicle, that receives electric power in a contactless manner from an electric supply apparatus using electromagnetic induction, and that transmits a data string for determining whether there is an obstacle between the electric supply apparatus and the electric reception apparatus, the electric reception apparatus comprising:
a receiving section that receives a first test data string transmitted from the electric supply apparatus using the electromagnetic induction in a coil;
a demodulation section that demodulates the first test data string received by the receiving section and that generates a second test data string; and
a transmitting section that transmits the second test data string generated by the demodulation section to the electric supply apparatus.
7. The electric reception apparatus according to claim 6 , further comprising an electric power control section that performs a control so that a transmission electric power level of the second test data string to be transmitted by the transmitting section increases in each transmission of the second test data string in a stepwise manner.
8. A charging system comprising:
an electric reception apparatus that is provided in a vehicle; and
an electric supply apparatus that supplies electric power in a contactless manner to the electric reception apparatus using electromagnetic induction, wherein
the electric supply apparatus includes:
a first transmitting section that transmits a first test data string including a predetermined data sequence to the electric reception apparatus using the electromagnetic induction in a coil;
an electric power control section that controls the first transmitting section to repeatedly transmit the first test data string from the transmitting section while increasing a transmission electric power level;
a first receiving section that receives a data string transmitted from the electric reception apparatus as a second test data string obtained by the electric reception apparatus via demodulation of the first test data string received by the electric reception apparatus; and
a determination section that determines whether the first test data string transmitted by the first transmitting section coincides with the second test data string received by the first receiving section, and determines whether there is an obstacle between the electric reception apparatus and the electric supply apparatus based on a transmission electric power level used for transmission of the first test data string from the transmitting section when the first test data string transmitted by the transmitting section coincides with the second test data string received by the receiving section, and
the electric reception apparatus includes:
a second receiving section that receives the first test data string from the electric supply apparatus;
a demodulation section that demodulates the first test data string received by the second receiving section and that generates the second test data string; and
a second transmitting section that transmits the second test data string generated by the demodulation section to the electric supply apparatus.
9. An obstacle detection method of determining whether there is an obstacle between an electric reception apparatus that is provided in a vehicle and an electric supply apparatus that supplies electric power in a contactless manner to the electric reception apparatus using electromagnetic induction, the method comprising:
transmitting a first test data string including a predetermined data sequence to the electric reception apparatus using the electromagnetic induction in a coil;
controlling transmission of the first test data string to be performed in the transmitting of the first test data string; and
determining whether there is an obstacle between the electric reception apparatus and the electric supply apparatus based on whether the first test data string transmitted in the transmitting of the first test data string coincides with a second test data string obtained by the electric reception apparatus via demodulation of the first test data string received by the electric reception apparatus.
10. The obstacle detection method according to claim 9 , wherein:
in the controlling of transmission of the first test data string, the transmission of the first test data string is controlled to be repeatedly performed while increasing a transmission electric power level; and
in the determining of whether there is an obstacle, whether there is an obstacle between the electric reception apparatus and the electric supply apparatus is determined based on a transmission electric power level used for transmission of the first test data string in the transmitting of the first test data string when the first test data string transmitted in the transmitting of the first test data string coincides with the second test data string obtained via the demodulation.