Object detection apparatus for an inductive charging system

1 . An inductive charging system comprising:

a ground pad module containing a coil and driving circuitry couplable with an electrical power supply configured to generate a magnetic field;

a car pad module containing a coil configured to receive energy from the magnetic field and driving circuitry couplable to deliver power to a battery in a vehicle; and

an object detection apparatus comprising:

a transmitter configured to transmit a signal;

a receiver having a field of view including a substantial portion of the magnetic field, the receiver configured to receive within the field of view a reflected signal of the transmitted signal; and

a signal processor configured to examine characteristics of the reflected signal as received by the receiver to identify a hazard condition in relation to the magnetic field; and

a wireless data link between the ground pad module and the car pad module to transfer therebetween data relating to operation thereof, wherein the wireless data link comprises a first antenna associated with the ground pad module and a second antenna associated with the car pad module;

wherein the object detection apparatus is coupled to the first antenna associated with the ground pad module or the second antenna associated with the car pad module;

wherein the object detection apparatus is operable at a first frequency contemporaneously with the wireless data link operable at a second frequency different from the first frequency; and

wherein the object detection apparatus and the wireless link are coupled to the first antenna of the ground pad module or the second antenna of the car pad module via respective filters respectively associated with the first frequency and the second frequency, wherein a first of the respective filters is configured to allow the reflected signal as received via the first frequency to pass to the object detection apparatus and to block a wireless signal associated with transfer of the data as received via the second frequency from passing to the object detection apparatus, while a second of the respective filters is configured to allow the wireless signal as received via the second frequency to pass to a communication element of the wireless data link and to block the reflected signal as received via the first frequency from passing to the communication element.

2 . The system as claimed in claim 1 , wherein the signal processor is operable to convert the reflected signal as received into an equivalent frequency domain signal, and further operable to examine the frequency domain signal to identify the hazard condition.

3 . The system as claimed in claim 2 , wherein the signal processor is operable to determine handedness of the frequency domain signal to identify the hazard condition.

4 . The system as claimed in claim 3 , wherein the signal processor is operable to determine position and/or direction of movement of an object in the magnetic field depending on the handedness of the frequency domain signal.

5 . The system as claimed in claim 1 , further comprising a reference store to hold data representing reference characteristics of a reference waveform, wherein the reflected signal as received comprises a waveform, wherein the signal processor is further configured to:

compare data representing characteristics of the waveform of the reflected signal as received with the reference characteristics of the reference waveform; and

identify the hazard condition depending on equivalence between the waveform of the reflected signal as received and the reference waveform.

6 . The system as claimed in claim 5 , wherein the reference characteristics comprise characteristics of the signal transmitted by the transmitter.

7 . The system as claimed in claim 5 , wherein the reference characteristics comprise respective frequency and/or phase of the signal transmitted by the transmitter and the reflected signal as received by the receiver.

8 . The system as claimed in claim 5 , wherein the reference characteristics are related to operating characteristics associated with energy transfer via the magnetic field.

9 . The system as claimed in claim 8 , wherein the reference characteristics are associated with efficiency of the energy transfer.

10 . The system as claimed in claim 5 , wherein the reference characteristics are determined by voltage and/or current signals associated with transfer of the energy via the magnetic field.

11 . The system as claimed in claim 1 , wherein the signal processor is operable to moderate detection of an object depending on a change corresponding to a change in height of the vehicle relative to a ground.

12 . The inductive charging system as claimed in claim 1 , wherein:

the object detection apparatus is coupled to the first antenna of the car pad module; and

the first antenna of the car pad module has the field of view that includes a volume of space between the ground pad module and the car pad module.

13 . A method of detecting a hazard condition in an object detection apparatus of an inductive charging system in which energy is transferred via a magnetic field between a ground pad module and a car pad module in a vehicle, and in which data relating to operation of the ground pad module and the car pad module is transferred therebetween via a wireless data link between the ground pad module and the car pad module, the wireless data link comprising a first antenna associated with the ground pad module and a second antenna associated with the car pad module, the method comprising:

transferring the data via the wireless data link between the ground pad module and the car pad module, the wireless data link being operable at a first frequency;

transmitting a signal and receiving within a field of view including a substantial portion of the magnetic field, a reflected signal of the signal as transmitted via the object detection apparatus, the object detection apparatus being operable at a second frequency contemporaneously with the wireless data link being operable at the first frequency different from the second frequency, wherein the object detection apparatus and the wireless link are coupled to the first antenna of the ground pad module or the second antenna of the car pad module via respective filters respectively associated with the first frequency and the second frequency, wherein a first of the respective filters allows the reflected signal as received via the second frequency to pass to the object detection apparatus and blocks a wireless signal associated with transfer of the data as received via the first frequency from passing to the object detection apparatus, while a second of the respective filters allows the wireless signal as received via the first frequency to pass to a communication element of the wireless data link and blocks the reflected signal as received via the second frequency from passing to the communication element; and

examining characteristics of the reflected signal as received to identify a hazard condition in relation to the magnetic field.

14 . The method as claimed in claim 13 , further comprising:

converting the reflected signal as received into an equivalent frequency domain signal; and

examining the frequency domain signal to identify the hazard condition.

15 . The method as claimed in claim 14 , further comprising determining handedness of the frequency domain signal to identify the hazard condition.

16 . The method as claimed in claim 15 , further comprising determining position and/or direction of movement of an object in the magnetic field depending on the handedness of the frequency domain signal.

17 . The method as claimed in claim 13 , wherein the inductive charging system comprises a reference store holding data representing reference characteristics of a reference waveform, wherein the reflected signal as received comprises a waveform, wherein the method further comprises:

comparing data representing characteristics of the waveform of the reflected signal as received with the reference characteristics of the reference waveform; and

identifying the hazard condition depending on equivalence between the waveform of the reflected signal as received and the reference waveform.

18 . The method as claimed in claim 17 , wherein the reference characteristics comprise characteristics of the signal as transmitted.

19 . The method as claimed in claim 17 , wherein the reference characteristics comprise respective frequency and/or phase of the signal as transmitted and the reflected signal as received.

20 . The method as claimed in claim 17 , wherein the reference characteristics are related to operating characteristics associated with energy transfer via the magnetic field.

21 . The method as claimed in claim 20 , wherein the reference characteristics are associated with efficiency of the energy transfer.

22 . The method as claimed in claim 17 , wherein the reference characteristics are determined by voltage and/or current signals associated with transfer of the energy via the magnetic field.

23 . The method as claimed in claim 13 , wherein the method further comprises moderating detection of an object depending on a change corresponding to a change in height of the vehicle relative to a ground.

24 . The method as claimed in claim 13 , wherein:

the object detection apparatus is coupled to the first antenna of the car pad module; and

the first antenna of the car pad module has the field of view that includes a volume of space between the ground pad module and the car pad module.