Foot presence sensing systems for active footwear
A foot presence sensor system for an active article of footwear can include a sensor housing configured to be disposed at or in an insole of the article, and a controller circuit, disposed within the sensor housing, configured to trigger one or more automated functions of the footwear based on a foot presence indication. In an example, the sensor system includes a capacitive sensor configured to sense changes in a capacitance signal in response to proximity of a body. A dielectric member can be provided between the capacitive sensor and the body to enhance an output signal from the sensor.
1. A system comprising:
a first sensor configured to sense a body position of a body, wherein the first sensor includes an insulating substrate having a substrate surface and at least two electrodes disposed on the substrate surface and fixedly spaced apart by a portion of the substrate;
a gap filling member disposed between the first sensor and a body-receiving cavity configured to receive the body; and
a signal generator configured to provide respective components of an electric signal to the electrodes to thereby generate an electric field, wherein the electric field extends between the electrodes and the electric field extends outside the first sensor and inside the body-receiving cavity that is configured to receive the body;
wherein the gap filling member is configured to influence a responsiveness of the first sensor to a change in the body position when the change in the body position is within at least a portion of the generated electric field inside the body-receiving cavity.
2. The system of claim 1 , wherein the gap filling member has a relative permittivity characteristic that is greater than the relative permittivity of air.
3. The system of claim 2 , wherein the gap filling member comprises neoprene.
4. The system of claim 1 , further comprising an article of footwear, wherein the first sensor is coupled to the footwear and configured to sense a foot location or a foot proximity relative to the first sensor.
5. The system of claim 4 , wherein the electrodes extend across a portion of a plane of an insole of the article of footwear.
6. The system of claim 1 , wherein the first sensor is configured to provide information about the sensed body position based on changes in the electric field.
7. The system of claim 6 , further comprising an article of footwear, wherein the first sensor is coupled to an under-foot portion of the article of footwear.
8. The system of claim 1 , further comprising a housing wherein the signal generator is disposed inside the housing;
wherein the first sensor includes a first sensor surface and an opposite second surface, wherein the first and second surfaces are parallel to the substrate surface of the first sensor, and wherein the first sensor surface is disposed on or adjacent to a first housing surface of the housing; and
wherein the gap filling member is disposed on the second surface of the first sensor and the gap filling member separates at least a portion of the first sensor from the body-receiving cavity.
9. A method comprising:
providing respective components of an alternating current excitation signal to electrodes of a first sensor to generate an electric field between the electrodes and extending away from the first sensor and inside a body-receiving cavity configured to receive a body, the first sensor configured to sense a body position of the body in the body-receiving cavity relative to the electric field and a first surface of the first sensor, and the electrodes being fixedly spaced apart on a shared substrate surface that is parallel to the first surface and adjacent to the cavity; and
receiving a response signal from the first sensor in response to the excitation signal, wherein a magnitude of the response signal is influenced by a dielectric characteristic of a gap filling member that is interposed between the first surface of the first sensor and the body-receiving cavity configured to receive the body, wherein the body-receiving cavity configured to receive the body and the electrodes of the first sensor are on respective opposite sides of the first surface of the first sensor.
10. The method of claim 9 , further comprising providing the gap filling member having a relative permittivity that is greater than the relative permittivity of air.
11. The method of claim 9 , wherein the response signal indicates a change in a position of a foot in an article of footwear.
12. The method of claim 9 , further comprising processing the response signal, using a processor circuit, to identify at least one of a footwear donning event or a footwear doffing event.
13. The method of claim 9 , further comprising processing the response signal, using a processor circuit, to identify a magnitude of a change in a position of a foot in an article of footwear.
14. The method of claim 13 , further comprising conditionally actuating an automated lacing engine based on the identified magnitude of the change in the position of the foot.
15. An article of footwear comprising:
a motorized tensioning device for controlling a position of a tensioning member;
a first sensor configured to sense a foot position inside a body-receiving cavity of the footwear, wherein the first sensor includes an insulating substrate having a substrate surface and at least two spaced apart electrodes on the substrate surface, wherein the electrodes are immobilized relative to each other and the substrate surface;
a gap filling member disposed between the first sensor and the body-receiving cavity of the footwear, wherein the gap filling member is configured to influence a responsiveness of the first sensor to a change in the foot position relative to an electric field provided by the electrodes and the electric field extends away from the first sensor and inside the body-receiving cavity; and
a processor circuit configured to conditionally actuate the motorized tensioning device based on information from the first sensor about the foot position.
16. The article of footwear of claim 15 , wherein the processor circuit comprises a signal generator configured to provide an alternating current drive signal to the electrodes of the first sensor, and wherein the electrodes are configured to generate the electric field in the cavity in response to the drive signal.
17. The article of footwear of claim 15 , wherein the first sensor is configured to sense a change in the foot position inside the cavity of the footwear.
18. The article of footwear of claim 15 , wherein the processor circuit is configured to use information from the first sensor to determine a presence or an absence of the foot from the cavity of the footwear, and the processor circuit is configured to actuate the motorized tensioning device based on the determined presence or absence of the foot.
19. The article of footwear of claim 15 , wherein the electrodes are disposed at or adjacent to a foot-facing surface of an insole of the article of footwear.
20. The article of footwear of claim 15 , wherein the electrodes are disposed at or adjacent to a foot arch-receiving portion of the article of footwear.