Systems, methods, and apparatus for foreign object detection loop based on inductive thermal sensing
AssigneeWiTricity Corporation
InventorHanspeter Widmer
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Abstract
This disclosure provides systems, methods and apparatus for detecting foreign objects. An apparatus for detecting a presence of an object is provided. The apparatus includes a coil configured to inductively sense a presence of an object based on an electrical characteristic of the coil that varies as a function of a temperature of the object when the object is exposed to an alternating magnetic field. The apparatus further includes a controller configured to detect a change in the electrical characteristic.
Claims23
An apparatus for detecting an object, comprising:
- a coil configured to inductively sense a presence of the object based on an electrical characteristic of the coil that varies as a function of a temperature of the object when the object is exposed to an alternating magnetic field;
- a controller configured to:
- detect a change in the electrical characteristic over time,
- determine a temperature response of the object, based upon the detected change in the electrical characteristic,
- schedule an exposure cycle for the magnetic field,
- compare the detected change in the electrical characteristic over at least a portion of time of the exposure cycle with the exposure cycle over the same period of time to identify a correlation between the detected change and the exposure cycle, and
- determine the presence of the object based on the detected correlation;
- a transmitter configured to transmit a signal to adjust the magnetic field exposure;
- and
- a receiver configured to receive a feedback signal indicating a timing schedule for the exposure cycle and a strength of the magnetic field exposure.
A method for detecting a presence of an object, comprising:
- generating an alternating magnetic field based upon an exposure cycle;
- sensing a presence of the object based on an electrical characteristic of a coil that varies as a function of a temperature of the object when the object is exposed to an alternating magnetic field;
- detecting a change in the electrical characteristic over time;
- determining a temperature response of the object, based upon the detected change in the electrical characteristic;
- scheduling an exposure cycle for the magnetic field;
- comparing the detected change in the electrical characteristic over at least a portion of time of the exposure cycle with the exposure cycle over the same period of time to identify a correlation between the detected change and the exposure cycle;
- determining the presence of the object based on the detected correlation;
- transmitting a signal to adjust the magnetic field exposure;
- and
- receiving a feedback signal indicating a timing schedule for the exposure cycle and a strength of the magnetic field exposure.
An apparatus for detecting an object, comprising:
- means for sensing a presence of the object based on an electrical characteristic of the sensing means that varies as a function of a temperature of the object when the object is exposed to an alternating magnetic field;
- means for detecting a change in the electrical characteristic over time;
- means for determining a temperature response of the object, based upon the detected change in the electrical characteristic;
- means for scheduling an exposure cycle for the magnetic field;
- means for comparing the detected change in the electrical characteristic of the sensing means over at least a portion of time of the exposure cycle with the exposure cycle over the same period of time to identify a correlation between the detected change and the exposure cycle;
- and
- means for determining the presence of the object based on the detected correlation.
Dependencies are inferred from the claim text.