External object detection using heat-sensitive materials and inductive sensing

Abstract

The present invention discloses a method and apparatus for detecting foreign objects using thermally sensitive materials and inductive sensing. In particular, a foreign object detection system includes a thermal sensing system that includes a thermally sensitive material having properties configured to change as a function of temperature. The foreign object detection system also includes an inductive sensing system including one or more sensing coils, wherein a change in an electrical characteristic of the one or more sensing coils indicates the presence of a foreign object. The foreign object detection system also includes a controller coupled to the thermal sensing system and the inductive sensing system, wherein the controller is configured to base the sensor on a measure of a property of the thermally sensitive material or a measure of an electrical characteristic of the one or more sensing coils. At least one to determine the presence of foreign objects.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to U.S. Application No. 15 / 620,548, filed June 12, 2017, which claims U.S. Provisional Patent No. 62 / 444,714, filed January 10, 2017 and filed February 10, 2017 US Provisional Patent No. 62 / 457,462 filed on , the contents of which are hereby incorporated by reference in their entirety. technical field [0003] The present application relates generally to wireless charging power transfer applications, and in particular to methods and apparatus for detecting foreign objects using thermally sensitive materials and inductive sensing. Background technique [0004] A wireless power transfer system (e.g., an inductive charging system for an electric vehicle) may include a ground-based wireless power transmitter (e.g., a base pad, a base wireless charging system, or some kind of system including a coupler (eg, a base coupler). other wireless power transmission device) that is configured to pr...

AI Technical Summary

Problems solved by technology

For example, a foreign object may be located on the wireless power transmitter and cause a portion of the wireless power transmitter to melt or burn, or may melt itself into the wireless power transmitter

Additionally, detecting foreign objects using certain foreign object detection (FOD) techniques may not be feasible, such as because the objects are small and difficult to detect, or may be too expensive

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