Nonlinear system identification for optimization of wireless power transfer

Abstract

A method of detecting whether a receiver coil 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 distinguishing the object as a receiver coil is near the transmit coil.

1 - 6 . (canceled) 
     
     
         7 . A method of detecting a receiver using a transmitter in a wireless power transfer system (WPTS), the method comprising:
 applying a signal to the transmitter;   in response to the signal being applied to the transmitter, receiving an output signal using the transmitter;   determining that the receiver is in range of the transmitter coil based on the output signal; and   in response to detecting the receiver is in range of the transmitter, initiating wireless power transfer from a transmitter coil in the transmitter to a receiver coil in the receiver using a drive signal.   
     
     
         8 . The method of  claim 7 , wherein determining the receiver is in range of the transmitter comprises:
 inputting the output signal into a system model representing the WPTS, the system model outputting that the receiver is in range of the transmitter based on the output signal, the system model also being used, in part, to reduce noise in the output signal.   
     
     
         9 . The method of  claim 8 , further comprising, before applying the signal to the transmitter:
 training the system model using training data based on a set of system configurations representing variations in at least one of a location of the receiver relative to the transmitter, a receiver orientation relative to the transmitter, a receiver temperature, a charge state of a battery coupled to the receiver, or another property of the battery.   
     
     
         10 . The method of  claim 8 , wherein the output signal is used as input into the system model to determine that another receiver is in range of the transmitter, the other receiver being configured to at least one of receive wireless power transfer from the transmitter or communicate data to the transmitter. 
     
     
         11 . The method of  claim 7 , further comprising:
 while the wireless power transfer occurs, applying a perturbation signal to the transmitter; and   communicating data produced by the perturbation signal from the receiver to the transmitter.   
     
     
         12 . The method of  claim 11 , wherein the data is transmitted using a first sensor operably coupled to the receiver coil in the receiver and received using a second sensor operably coupled to the transmitter coil in the transmitter. 
     
     
         13 . The method of  claim 11 , wherein the drive signal is at a first frequency and the data is transmitted at a second frequency. 
     
     
         14 . The method of  claim 11 , further comprising:
 determining, using the data, an efficiency of the wireless power transfer; and   adjusting the first frequency so as to increase the efficiency of the wireless power transfer.   
     
     
         15 . The method of  claim 11 , wherein the drive signal and the perturbation signal are superimposed. 
     
     
         16 . A method of finding a drive signal to apply to a transmitter in a wireless power transfer system (WPTS), said method comprising:
 in response to detecting a receiver is in range of the transmitter, initiating a wireless power transfer from a transmitter coil in the transmitter to a receiver coil in the receiver using an initial drive signal;   while the wireless power transfer occurs, applying a perturbation signal to the transmitter;   receiving an output signal in response to the perturbation signal;   calibrating, using the output signal and the perturbation signal, a system model representing the WPTS;   conducting, using the system model, a search for the drive signal that changes an output of the WPTS; and   applying the drive signal to the transmitter coil.   
     
     
         17 . The method of  claim 16 , wherein conducting the search for the drive signal comprises:
 simulating the output using the system model while adjusting the drive signal until the output satisfies a criterion.   
     
     
         18 . The method of  claim 17 , wherein the criterion comprises meeting a threshold value. 
     
     
         19 . The method of  claim 17 , wherein adjusting the drive signal comprises adjusting a frequency of the drive signal. 
     
     
         20 . The method of  claim 16 , wherein the drive signal and the perturbation signal are superimposed. 
     
     
         21 . The method of  claim 17 , wherein conducting the search for the drive signal comprises:
 inputting a plurality of frequencies into the system model simultaneously thereby decreasing the amount of time to find the drive signal.   
     
     
         22 . The method of  claim 16 , further comprising:
 transmitting data from the receiver to the transmitter.   
     
     
         23 . The method of  claim 22 , wherein the data is transmitted using a first sensor operably coupled to the receiver coil in the receiver and received using a second sensor operable coupled to the transmitter coil in the transmitter. 
     
     
         24 . The method of  claim 22 , wherein the wireless power transfer charges the receiver at a charging rate, wherein conducting the search for the drive signal comprises:
 determining, using the data, an efficiency of the wireless power transfer; and   adjusting the drive signal to change the efficiency or the charging rate, the efficiency or the charging rate being the output.   
     
     
         25 . The method of  claim 22 , wherein conducting the search for the drive signal comprises:
 determining, using the data, a property of a battery operably coupled to the receiver, the property being at least one of a charge state or a stored energy; and   adjusting the drive signal to change the property, the property being the output.   
     
     
         26 . A wireless power transfer system (WPTS) comprising:
 a transmitter having a transmitter coil; and   a controller, operably coupled to the transmitter, to:
 apply a signal to the transmitter; 
 in response to the signal being applied to the transmitter, receiving an output signal using the transmitter; 
 using the output signal as an input into a first system model representing the WPTS and configured to determine that a receiver is in range of the transmitter, the first system model being used, in part, to reduce noise in the signal; and 
 in response to detecting the receiver is in range of the transmitter, initiating a wireless power transfer from the transmitter coil to a receiver coil in the receiver using an initial drive signal. 
   
     
     
         27 . The WPTS of  claim 26 , wherein the controller is further configured to:
 while the wireless power transfer occurs, applying a perturbation signal to the transmitter;   receiving a second output signal in response to the perturbation signal;   calibrating, using the second output signal and the perturbation signal, a second system model representing the WPTS;   conducting a search for a drive signal that changes an output of the WPTS, the search comprising simulating the output using the second system model while adjusting the drive signal until the output satisfies a criterion; and   applying the drive signal applied to the transmitter coil.   
     
     
         28 . The WPTS of  claim 27 , wherein the criterion comprises meeting a threshold value. 
     
     
         29 . The WPTS of  claim 27 , wherein the wireless power transfer charges the receiver at a charging rate, wherein conducting the search for the drive signal comprises:
 determining, using the second output signal, an efficiency of the wireless power transfer; and   adjusting the drive signal to change the efficiency or the charging rate, the efficiency or the charging rate being the output.   
     
     
         30 . The WPTS of  claim 27 , further comprising:
 a battery, coupled to the receiver, having a stored energy, wherein applying the drive signal comprises modulating the drive signal such that the stored energy satisfies the criterion.