TECHNICAL FIELD

The disclosure relates to wireless power transfer systems and the more safe and efficient transfer of energy. More particularly, the disclosure relates to foreign object detection using sensors in wireless power and data transfer applications.

BACKGROUND

Wireless power transfer systems transfer electrical energy from one circuit to an adjacent circuit. Wireless power transfer systems may be used to supply power, charge batteries, transfer data and the like. One method of wireless power transfer is to utilize a variable current on a primary transmitter coil to create a varying magnetic field and a voltage, in a secondary receiver coil. The primary transmitter coil is responsive to a transmitting device that is transmitting energy. A receiving device is responsive to the secondary receiver coil that is receiving at least part of the transmitted energy. In another example of the disclosure the primary transmitter coil is coupled to a transmitter mat. The secondary receiving coil is placed adjacent to the transmitter mat and the secondary receiver coil electrically couples to the primary transmitter coil.

Power transfer is intended to occur between the transmitting device and the receiving device. Foreign objects receiving a portion of this transmitted energy decrease the system efficiency. These foreign objects may provide a path where eddy currents may be generated causing electrically induced thermal dissipation. During wireless power transfer, ohmic losses may be incurred in addition to magnetic field losses thereby increasing the difficulty in determining whether the transmitting device is communicating solely with the receiving device or the receiving device in addition to a foreign object. Variations in placement of the primary transmitter coil and the secondary receiver coil may decrease the efficiency of the magnetic field coupling, and thus the system efficiency. The foregoing may thus increase the general difficulty in determining whether a system is transferring electrical energy to energy dissipating foreign objects. Due to these and other problems and potential problems, improved detection of foreign objects using sensors would be useful and advantageous contributions to the arts.

SUMMARY

In carrying out the principles of the present disclosure, the device and method provides advances in the arts with apparatus and method directed to the transfer of power and/or data utilizing foreign object detection. In other examples, systems and methods include capabilities for power and/or data transfer.

According to aspects of the disclosure, examples include a wireless power transfer foreign object detector comprising, at least one foreign object detector providing at least one foreign object detection signal and at least one primary transmitter coil providing at least one primary transmitter signal. The primary transmitter coil is responsive to the at least one foreign object detection signal.

A further example would comprise a wireless power transfer foreign object detector comprising, a transmitter mat, at least one foreign object detector coupled to the transmitter mat, the at least one foreign object detector providing at least one foreign object detection signal, at least one primary transmitter coil coupled to the transmitter mat. The at least one primary transmitter coil provides at least one primary transmitter signal. The primary transmitter coil is responsive to the at least one foreign object detection signal. At least one secondary receiver coil is electronically responsive to the at least one primary transmitter coil. The at least one secondary receiver coil provides at least secondary receiver signal. The at least one foreign object detector senses at least one magnetic or electric field characteristic of the at least one secondary receiver coil.

Another example would comprise a wireless power transfer foreign object detector comprising, a transmitter mat, at least one foreign object detector connected to the mat and providing at least one foreign object detection signal upon interaction with at least one foreign object. The at least one foreign object detector senses at least one of a physical interaction with the at least one foreign object and an electrical interaction with the at least one foreign object. At least one primary transmitter coil provides at least one primary transmitter signal, the primary transmitter coil is responsive to the at least one foreign object detection signal.

An alternate example would comprise a method of wireless power transfer foreign object detection comprising the steps of, detecting at least one of a physical interaction with at least one foreign object and an electrical interaction with the at least one foreign object and providing at least one foreign object detection signal. The method comprises the step of modulating at least one primary transmitter signal in response to the at least one foreign object detection signal, where the modulation comprises at least one of reducing the at least one primary transmitter signal and redirecting the at least one primary transmitter signal in response to the at least one foreign object detection signal.

A further example would comprise a method of wireless power transfer foreign object detection comprising the steps of, detecting at least one magnetic or electric field characteristic, comparing the detected at least one magnetic or electric field characteristic to a magnetic or electric field characteristic look up table. The method further comprises modulating at least one primary transmitter signal in response to the compared characteristic, wherein the modulation comprises at least one of reducing the at least one primary transmitter signal and redirecting the at least one primary transmitter signal in response to the at least one magnetic or electric field characteristic.

The disclosure has advantages which are not limited to one or more of, improved coupled inductor system power transfer and improved data transmission functionality. These and other potential advantageous, features, and benefits of the present disclosure can be understood by one skilled in the arts upon careful consideration of the detailed description of representative examples of the disclosure in connection with the accompanying drawings.

