Systems, methods, and apparatus for radar-based detection of objects in a predetermined space

Patent metadata

Field	Value
Publication number	US-9772401-B2
Application number	US-201414335296-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Mar 17, 2014
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

This disclosure provides apparatuses and methods for detecting foreign objects. An apparatus for detecting a presence of an object comprises at least one radar antenna attached to a wirelessly chargeable vehicle. The at least one radar antenna is configured to transmit a radar signal into a space between a wireless power receiver of the vehicle and a wireless charger as the vehicle moves in a primary direction of movement of the vehicle and receive the radar signal. The apparatus further comprises a radar processing circuit configured to determine a presence of the object in the space based on at least one characteristic of the received radar signal. The radar processing circuit is further configured to provide an indication to receive power from the wireless charger based at least in part on the determining the presence of the object.

First claim

What is claimed is:

1. An apparatus for detecting a presence of an object, comprising:
a printed circuit board;
at least one radar transmit antenna disposed on a center portion of the printed circuit board;
a plurality of radar receive antennas disposed on a periphery of the printed circuit board, each configured to receive a radar signal from the at least one radar transmit antenna; and
a first transmit coil of a wireless charger disposed over the printed circuit board.

2. The apparatus of claim 1 , the first transmit coil encircling the at least one radar transmit antenna.

3. The apparatus of claim 1 , further comprising a second transmit coil of the wireless charger disposed adjacent to the first transmit coil, the at least one transmit antenna disposed adjacent to a corner of and between each of the first and second transmit coils.

4. The apparatus of claim 1 , further comprising a second transmit coil of the wireless charger disposed adjacent to the first transmit coil and the at least one radar transmit antenna comprising a first radar transmit antenna and a second radar transmit antenna, the first transmit coil encircling the first radar transmit antenna and the second transmit coil encircling the second radar transmit antenna.

5. The apparatus of claim 1 , further comprising a radar processing circuit.

6. The apparatus of claim 5 , wherein the radar processing circuit is configured to cancel crosstalk between the at least one radar transmit antenna and the plurality of radar receive antennas by:
disconnecting the at least one radar transmit antenna and the plurality of radar receive antennas from the radar processing circuit;
determining a crosstalk signal induced in the radar processing circuit; and
subtracting the crosstalk signal from the received radar signal.

7. The apparatus of claim 5 , wherein the radar processing circuit is configured to equalize an impulse response of the apparatus by:
measuring the impulse response of the apparatus while a transmit antenna port of a radar processing unit is connected to a receive antenna port of the radar processing unit;
applying an equalizing filter having an inverse function of the measured impulse response to the received radar signal.

8. The apparatus of claim 5 , wherein the radar processing circuit is configured to detect the presence of the object utilizing at least one of:
time-differential detection, wherein the radar processing circuit is configure to:
filter the received radar signal;
determine the presence of the object when the filtered received radar signal exceeds a predetermined threshold; and

space-differential detection, wherein the radar processing circuit is configure to determine the presence of the object when the received radar signal from at least one of the subset of the plurality of radar receive antennas exceeds a predetermined threshold and the received radar signal from at least one other of the subset of the plurality of radar receive antennas does not exceed the predetermined threshold.

9. A method for operating an apparatus for detecting a presence of an object, comprising:
transmitting a radar signal from at least one radar transmit antenna disposed on a center portion of a printed circuit board;
receiving the radar signal utilizing at least a subset of a plurality of radar receive antennas disposed on a periphery of the printed circuit board;
determining a presence of the object utilizing a radar processing circuit based on at least one characteristic of the received radar signal; and
supplying power to a first transmit coil of a wireless charger disposed over the printed circuit board based at least in part on the determining the presence of the object.

10. The method of claim 9 , the first transmit coil encircling the at least one radar transmit antenna.

11. The method of claim 9 , further comprising supplying power to a second transmit coil of the wireless charger disposed adjacent to the first transmit coil, the at least one transmit antenna disposed adjacent to a corner of and between each of the first and second transmit coils.

12. The method of claim 9 , the at least one radar transmit antenna comprising a first radar transmit antenna and a second radar transmit antenna, the first transmit coil encircling the first radar transmit antenna and a second transmit coil encircling the second radar transmit antenna.

13. The method of claim 9 , further comprising cancelling crosstalk between the at least one radar transmit antenna and the plurality of radar receive antennas, the cancelling comprising:
disconnecting the at least one radar transmit antenna and the plurality of radar receive antennas from a radar processing circuit;
determining a crosstalk signal induced in the radar processing circuit; and
subtracting the crosstalk signal from the received radar signal.

14. The method of claim 9 , further comprising equalizing an impulse response of the apparatus, the equalizing comprising:
measuring the impulse response while a transmit antenna port of a radar processing unit is connected to a receive antenna port of the radar processing unit;
applying an equalizing filter having an inverse function of the measured impulse response to the received radar signal.

15. The method of claim 9 , wherein the determining the presence of the object comprises at least one of:
time-differential detection comprising:
filtering the received radar signal;
determining the presence of the object when the filtered received radar signal exceeds a predetermined threshold; and

space-differential detection comprising determining the presence of the object when the received radar signal from at least one of the subset of the plurality of radar receive antennas exceeds a predetermined threshold and the received radar signal from at least one other of the subset of the plurality of radar receive antennas does not exceed the predetermined threshold.

16. An apparatus for detecting a presence of an object, comprising:
at least one radar antenna attached to a wirelessly chargeable vehicle and configured to:
transmit a radar signal into a space between a wireless power receiver of the vehicle and a wireless charger as the vehicle moves in a primary direction of movement of the vehicle;
receive the radar signal;

a radar processing circuit configured to:
determine a presence of the object in the space based on at least one characteristic of the received radar signal utilizing at least one of:
time-differential detection, wherein the radar processing circuit is configure to:
filter the received radar signal;
determine the presence of the object when the filtered received radar signal exceeds a predetermined threshold; and
space-differential detection, wherein the radar processing circuit is configured to determine the presence of the object when the received radar signal from one of the at least one radar antennas exceeds a predetermined threshold and the received radar signal from another of the at least one radar antennas does not exceed the predetermined threshold; and

provide an indication to receive power from the wireless charger based at least in part on the determining the presence of the object.

17. The apparatus of claim 16 , the at least one radar antenna configured to be stored in a recess of the vehicle when not in use and deployed to a height outside of the recess sufficient to determine the presence of the object when in use.

18. The apparatus of claim 16 , the at least one radar antenna configured to move in one of a rotating or swing

Assignees

• Qualcomm Inc

Inventors

• Widmer Hanspeter
• Sieber Lukas
• Daetwyler Andreas
• Bittner Markus

Classifications

• H02J2105/37

  exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV] · CPC title

• G01S7/032

  Constructional details for solid-state radar subsystems · CPC title

• H04B5/0037

  Electricity · mapped topic

• G01S13/04 Primary

  Systems determining presence of a target (based on relative movement of target G01S13/56) · CPC title

• H02J50/12

  of the resonant type · CPC title