Foreign object detection

• US 9,893,549 B2
• Filed: 10/25/2012
• Issued: 02/13/2018
• Est. Priority Date: 10/25/2012
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Borngrber, Frank
• Primary Examiner(s): Lee, Jonathan S
• Application Number:
  US14/436,999
• Publication Number:
  US 20150288214A1
• Time in Patent Office: 1,937 Days
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01V 3/10 using induction coils
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06T 1/0007 Image acquisition
• CPC Class Codes: G06T 2207/10004 Still image; Photographic image
• CPC Class Codes: G06T 2207/30 Subject of image; Context of image processing
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 7/00045 Authentication, i.e. circuits for checking compatibility between one component, e.g. a battery or a battery charger, and another component, e.g. a power source
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters

Abstract

It is inter alia disclosed to determining whether an object detected (160) based on at least one capacitance representative of at least one capacitance representative sensed by at least one capacitance sensing element (111, 112, 113) of an apparatus (100) corresponds to a predefined type of objects, the apparatus (100) further comprising a wireless charging unit (140), wherein the at least one capacitance sensing element (111, 112, 113) is at least partially placed in proximity to the wireless charging unit (140).

Claims

1. A method performed by an apparatus, comprising:

determining whether an object detected based on at least one capacitance, representative of at least one capacitance representative sensed by at least one capacitance sensing element of said apparatus, corresponds to a predefined type of objects,

wherein the apparatus further comprises a wireless charging unit, and

wherein the at least one capacitance sensing element is at least partially placed in proximity to the wireless charging unit,

wherein said at least one capacitance sensing element represents a plurality of capacitance sensing elements,

wherein the apparatus further comprises a touch sensitive interface and the plurality of capacitance sensing elements is part of the touch sensitive interface,

wherein said touch sensitive interface comprises a display, and

wherein the determining whether the object detected corresponds to the predefined type of objects is performed based on training data in which the display is used in performing a training procedure to learn predefined objects being associated with the predefined type of objects.

2. The method according to claim 1, further comprising:

capturing an image of the object detected based on at least one capacitance representative, sensed by at least one capacitance sensing element of the plurality of capacitance sensing elements, and

wherein said determining whether an object detected based on at least one sensed capacitance of said at least one sensed capacitance corresponds to a predefined type of object comprises;

determining whether the captured image of the object detected at least partially matches with an image of an object associated with the predefined type of objects.

3. The method according to claim 1, wherein said determining whether an object detected based on at least one sensed capacitance of said at least one sensed capacitance corresponds to a predefined type of object comprises:

determining a feature of the object based on at least one sensed capacitance representative, and

determining whether the feature at least partially corresponds to a predefined feature of at least one predefined feature associated with said predefined type of objects,

wherein said feature represents a shape of the object, and

wherein the determining whether the feature at least partially corresponds to a predefined feature comprises comparing information on a size and the shape of the object detected with a size associated with a respective predefined object, and, when the size of the object detected is less than a size threshold, it is determined that the object detected does not match with the respective predefined object, even if a type of shape of the object detected at least partially corresponds to the type of shape associated with this predefined object.

4. The method according to claim 3, wherein said shape of the object is determined based on an edge detection.

5. The method according to claim 1, wherein the apparatus comprises at least one temperature sensor, and wherein said determining whether an object corresponds to the predefined type of objects is further based on a temperature measured by said at least one temperature sensor.

6. A non-transitory computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to:

determine whether an object detected based on at least one capacitance, representative of at least one capacitance representative sensed by at least one capacitance sensing element of said apparatus, corresponds to a predefined type of objects,

wherein the apparatus further comprises a wireless charging unit, and

wherein the at least one capacitance sensing element is at least partially placed in proximity to the wireless charging unit,

wherein said at least one capacitance sensing element represents a plurality of capacitance sensing elements,

wherein the apparatus further comprises a touch sensitive interface and the plurality of capacitance sensing elements is part of the touch sensitive interface,

wherein said touch sensitive interface comprises a display, and

wherein determining whether the object detected corresponds to the predefined type of objects is performed based on training data in which the display is used in performing a training procedure to learn predefined objects being associated with the predefined type of objects.

7. An apparatus, comprising:

a wireless charging unit;

at least one capacitance sensing element at least partially placed in proximity to the wireless charging unit, wherein each capacitance sensing element is configured to sense a capacitance representative; and

a detection unit configured to determine whether an object detected based on at least one capacitance representative sensed by at least one capacitance sensing element of said at least one capacitance sensing element corresponds to a predefined type of objects,

wherein said at least one capacitance sensing element represents a plurality of capacitance sensing elements,

wherein the apparatus further comprises a touch sensitive interface and the plurality of capacitance sensing elements is part of the touch sensitive interface,

wherein said touch sensitive interface comprises a display, and

wherein determining whether the object detected corresponds to the predefined type of objects is performed based on training data in which the display is used in performing a training procedure to learn predefined objects being associated with the predefined type of objects.

8. The apparatus according to claim 7, wherein the detection unit is configured to capture an image based on at least one capacitance representative, sensed by at least one capacitance sensing element of the plurality of capacitance sensing elements, and wherein said determining whether an object detected based on at least one sensed capacitance of said at least one sensed capacitance corresponds to a predefined type of object comprises:

determining whether the captured image at least partially matches with an image of an object associated with the predefined type of objects.

9. The apparatus according to claim 7, wherein said determining whether an object detected based on at least one sensed capacitance of said at least one sensed capacitance corresponds to a predefined type of object comprises:

determining a feature of the object based on at least one sensed capacitance representative, and

determining whether the feature at least partially corresponds to a predefined feature of at least one predefined feature associated with said predefined type of objects,

wherein said feature represents a shape of the object, and

wherein the determining whether the feature at least partially corresponds to a predefined feature comprises comparing information on a size and the shape of the object detected with a size associated with a respective predefined object, and, when the size of the object detected is less than a size threshold, it is determined that the object detected does not match with the respective predefined object, even if a type of shape of the object detected at least partially corresponds to the type of shape associated with this predefined object.

10. The apparatus according to claim 7, wherein said determining whether an object detected based on at least one sensed capacitance of said at least one sensed capacitance corresponds to a predefined type of object comprises:

determining a feature of the object based on at least one sensed capacitance representative, and

determining whether the feature at least partially corresponds to a predefined feature of at least one predefined feature associated with said predefined type of objects,

wherein said feature represents a shape of the object, and

wherein said determining whether the shape at least partially corresponds to a predefined shape associated with said predefined type of object comprises;

calculating for at least one predefined feature of the at least one predefined feature associated with said predefined type of object a correlation value being indicative of a correlation between the respective predefined feature and the determined feature, and

determining whether a correlation value exceeds a predefined correlation value.

11. A method performed by an apparatus, comprising:

detecting an object based on at least one sensed capacitance, representative of the at least one capacitance representative sensed by at least one capacitance sensing element of said apparatus, the apparatus further comprising a wireless charging unit, wherein the at least one capacitance sensing element is placed at least partially in proximity to the wireless charging unit;

verifying whether the detected object shall be associated with a predefined type of objects; and

if said detected object shall be associated with the predefined type of object, associating the detected object with the predefined type of objects,

wherein said at least one capacitance sensing element represents a plurality of capacitance sensing elements,

wherein the apparatus further comprises a touch sensitive interface and the plurality of capacitance sensing elements is part of the touch sensitive interface,

wherein said touch sensitive interface comprises a display, and

wherein verifying whether the detected object shall be associated with the predefined type of objects is performed based on training data in which the display is used in performing a training procedure to learn predefined objects being associated with the predefined type of objects.

12. The method according to claim 11, wherein said verifying is further performed based on:

user interaction for indicating whether a detected object shall be associated with the predefined type of objects.

13. A computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to:

detect an object based on at least one sensed capacitance, representative of the at least one capacitance representative sensed by at least one capacitance sensing element of said apparatus, the apparatus further comprising a wireless charging unit,

wherein the at least one capacitance sensing element is placed at least partially in proximity to the wireless charging unit to verify whether the detected object shall be associated with a predefined type of objects, and, if said detected object shall be associated with the predefined type of object, to associate the detected object with the predefined type of objects,

wherein said at least one capacitance sensing element represents a plurality of capacitance sensing elements,

wherein the apparatus further comprises a touch sensitive interface and the plurality of capacitance sensing elements is part of the touch sensitive interface,

wherein said touch sensitive interface comprises a display, and

wherein verifying whether the detected object shall be associated with the predefined type of objects is performed based on training data in which the display is used in performing a training procedure to learn predefined objects being associated with the predefined type of objects.

14. An apparatus, comprising:

a wireless charging unit;

at least one capacitance sensing element at least partially placed in proximity to the wireless charging unit, wherein each capacitance sensing element is configured to sense a capacitance representative;

a detection unit configured to detect an object based on at least one sensed capacitance, representative of the at least one capacitance representative sensed by the at least one capacitance sensing element of said apparatus, to verify whether the detected object shall be associated with a predefined type of objects, and, if said detected object shall be associated with the predefined type of object, to associate the detected object with the predefined type of objects,

wherein said at least one capacitance sensing element represents a plurality of capacitance sensing elements,

wherein the apparatus further comprises a touch sensitive interface and the plurality of capacitance sensing elements is part of the touch sensitive interface,

wherein said touch sensitive interface comprises a display, and

wherein verifying whether the detected object shall be associated with the predefined type of objects is performed based on training data in which the display is used in performing a training procedure to learn predefined objects being associated with the predefined type of objects.