DYNAMIC MUTUAL SENSING FOREIGN OBJECT DETECTION LOOPS
First Claim
1. An apparatus for detecting a presence of a foreign object within a region for wirelessly transferring power to charge an electric vehicle, the apparatus comprising:
- a foreign object detection (FOD) structure including;
a transmitting loop structure;
a receiving loop structure galvanically isolated from the transmitting loop structure and positioned relative to the transmitting loop structure such that a magnetic field generated by the transmitting loop structure induces a first voltage in the receiving loop structure, wherein the first voltage is below a threshold value; and
a control circuit configured to drive the transmitting loop structure and detect a change in a magnitude of the first voltage in the receiving loop structure in response to the presence of the foreign object within the magnetic field.
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Accused Products
Abstract
Techniques for detecting a presence of a foreign object within a region for wirelessly transferring power to charge an electric vehicle are discloses. An example apparatus according to the disclosure includes a foreign object detection (FOD) structure including a transmitting loop structure, a receiving loop structure galvanically isolated from the transmitting loop structure and positioned relative to the transmitting loop structure such that a magnetic field generated by the transmitting loop structure induces a first voltage in the receiving loop structure, wherein the first voltage is below a threshold value, and a control circuit configured to drive the transmitting loop structure and detect a change in a magnitude of the first voltage in the receiving loop structure in response to the presence of the foreign object within the magnetic field.
14 Citations
30 Claims
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1. An apparatus for detecting a presence of a foreign object within a region for wirelessly transferring power to charge an electric vehicle, the apparatus comprising:
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a foreign object detection (FOD) structure including; a transmitting loop structure; a receiving loop structure galvanically isolated from the transmitting loop structure and positioned relative to the transmitting loop structure such that a magnetic field generated by the transmitting loop structure induces a first voltage in the receiving loop structure, wherein the first voltage is below a threshold value; and a control circuit configured to drive the transmitting loop structure and detect a change in a magnitude of the first voltage in the receiving loop structure in response to the presence of the foreign object within the magnetic field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of detecting a foreign object on a wireless charging base pad, comprising:
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determining a transmission signal and an expected received signal for a foreign object detection (FOD) loop, wherein the FOD loop includes a transmitting loop and a receiving loop; generating the transmission signal on the transmitting loop; measuring a received signal with the receiving loop; and detecting the foreign object based on a comparison of the received signal with the expected received signal. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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21. A foreign object detection apparatus, comprising:
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a transmitting loop structure in a first magnetic flux orientation; a receiving loop structure in a second magnetic flux orientation, wherein the receiving loop structure is galvanically isolated from the transmitting loop structure and positioned relative to the transmitting loop structure such that a magnetic field generated by the transmitting loop structure generates an expected electrical characteristic in the receiving loop structure; a control circuit configured to drive the transmitting loop structure and detect a change in the expected electrical characteristic in the receiving loop structure in response to a presence of a foreign object within the magnetic field; and a memory unit operably coupled to the control circuit and configured to store an expected electrical characteristic value corresponding to the expected electrical characteristic value the transmitting loop structure generates in the receiving loop structure. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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29. An apparatus for detecting a foreign object, comprising:
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means for determining a transmission signal and an expected received signal for a foreign object detection (FOD) loop, wherein the FOD loop includes a transmitting loop means in a first magnetic flux orientation and a receiving loop means in a second magnetic flux orientation such that an induced voltage in the receiving loop means is approximately zero in the absence of a foreign object; means for generating the transmission signal on the transmitting loop means; means for measuring a received signal with the receiving loop means; and means for detecting a foreign object based on a comparison of the received signal with the expected received signal. - View Dependent Claims (30)
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Specification