Load localisation

The method of any preceding claim, wherein determining the position of the object relative to the array with reference to the input signature comprises using a trained neural network to determine the position of the object from the input signature, wherein the trained neural network has been trained using a plurality of signatures for which the position of a test object is known.

The method of any preceding claim, wherein at least one resonator element of the array is a controllable resonator that is switchable from an on state to an off state using a control signal.

The method of any of the preceding claims, wherein the input signature corresponds with a first configuration of the array, the method further comprising:

• reconfiguring the array into a second configuration and determining a further signature of the element of the array;
• wherein determining the position of the object relative to the array is with reference to both the input signature and the further signature.

The method of any preceding claim, wherein the object comprises a plurality of objects, wherein each of the plurality of objects is positioned above a different resonator element of the array.

The method of any preceding claim, further comprising, subsequent to determining the position of the object, configuring the array to improve the efficiency of power transfer from a powered resonator element of the array to the object.

The method of any preceding claim, wherein the probe resonator is positioned to avoid a line of symmetry of the array.

Apparatus for inductive wireless power transfer, comprising:

• an array of resonators in which adjacent resonators are electromagnetically coupled such that they support inter-element excitation waves propagating through the array;
• wherein the array of resonators comprises a probe resonator that includes an impedance measurement module for determining an input signature of the probe resonator, and
• further comprising a processor configured to determine the position of an object that is inductively coupled to the array from an signature measured by the impedance measurement module.

The apparatus of any preceding claim, wherein determining the position of the object relative to the array with reference to the input impedance spectrum comprises using a trained neural network to determine the position of the object from the input signature, wherein the trained neural network has been trained using a plurality of signatures for which the position of a test object is known.

The apparatus of any preceding claim, wherein at least one resonator element of the array is a controllable resonator that is switchable from an on state to an off state using a control signal.

The apparatus of any preceding claim, wherein the object comprises a plurality of objects, wherein each of the plurality of objects is positioned above a different resonator element of the array.

The apparatus of any preceding claim, wherein the apparatus comprises a powered resonator configured to transfer electrical power to the array for wirelessly powering an object adjacent to the array, and the processor is configured to, after determining the position of the object, configure the array to improve the efficiency of power transfer from a the powered resonator element of the array to the object.

A method for localising a target device coupled to an array of resonators, comprising:

• conducting a search for the target device by adjusting parameters of the array to vary the distribution of current therein, while monitoring the input impedance of the at least one powered electrical resonator of the array.