Nonlinear system identification for object detection in a wireless power transfer system
Inventors
Lafontaine, Serge R. • Hunter, Ian W.
Assignees
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Publication Number
US-9983243-B2
Publication Date
2018-05-29
Expiration Date
Abstract
A method of detecting whether a foreign object is near a transmit coil in a wireless power transfer system (WPTS), the method involving: applying a pseudo-random signal to the transmit coil; while the pseudo-random signal is being applied to the transmit coil, recording one or more signals produced within the WPTS in response to the applied pseudo-random signal; by using the one or more recorded signals, generating a dynamic system model for some aspect of the WPTS; and using the generated dynamic system model in combination with stored training data to determine whether an object having characteristics recognizable from the stored training data as characteristic of the foreign object is near the transmit coil.
Core Innovation
The invention relates to wireless power transfer in a wireless power transfer system (WPTS) with a transmit coil. A pseudo-random signal is applied to the transmit coil, and one or more signals produced within the WPTS in response to the applied pseudo-random signal are recorded while the pseudo-random signal is being applied. Using the recorded signals, a system model for some aspect of the WPTS is generated.
The generated system model is used together with stored training data to determine whether an object having characteristics recognizable from the stored training data as characteristic of the foreign object is near the transmit coil. When the object is determined to be near the transmit coil based on the stored training data, a controller prevents wireless power transfer from taking place.
The invention further includes dynamic and nonlinear system modeling of aspects of the WPTS using nonlinear system identification. The selected model may include a dynamic linear part and a static nonlinear part, and may be a Wiener system. Stored training data may be represented with a stored filter function that, together with the generated dynamic system model, produces an output signal indicating whether a recognizable foreign object is near the transmit coil.
Claims Coverage
Two independent claims are provided. The inventive coverage centers on pseudo-random excitation, response recording, system model generation, and training-data based recognition of a foreign object near the transmit coil, with prevention of wireless power transfer when such an object is detected.
Pseudo-random excitation of transmit coil for response recording
Applying a pseudo-random signal to the transmit coil and recording one or more signals produced within the WPTS in response to the applied pseudo-random signal.
System model generation from recorded response
Using the one or more recorded signals to generate a system model for some aspect of the WPTS.
Training-data based recognition of foreign-object characteristics
Using the generated system model in combination with stored training data to determine whether an object having characteristics recognizable from the stored training data as characteristic of the foreign object is near the transmit coil.
Preventing wireless power transfer upon foreign-object detection
If the object having characteristics recognizable from the stored training data as characteristic of the foreign object is near the transmit coil, preventing a wireless power transfer from taking place.
WPTS controller with model-based determination
A wireless power transfer system comprising a controller with a memory storing training data characterizing a foreign object near the transmit coil and a processor system programmed to apply a pseudo-random signal, record one or more signals in response, generate a system model, and use the generated system model in combination with stored training data to determine whether the object is near the transmit coil.
Across the independent claims, the inventive coverage centers on pseudo-random excitation, recording transmit-coil response signals, generating a system model, and using stored training data to recognize a foreign object near the transmit coil, with explicit prevention of wireless power transfer when the recognizable foreign-object condition is met.
Stated Advantages
Prevents a wireless power transfer from taking place when an object recognizable from stored training data as characteristic of the foreign object is near the transmit coil.
Documented Applications
Detecting whether a foreign object is near a transmit coil in a wireless power transfer system (WPTS) and preventing wireless power transfer from taking place when detected.
Wireless power transfer system operation that uses a controller storing training data characterizing a foreign object near the transmit coil to determine foreign-object proximity and prevent wireless power transfer.
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