Active footwear sensor calibration
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, and the sensor is configured to sense changes in a foot proximity to the sensor in footwear. A baseline or reference condition for the capacitive sensor can be updated to accommodate different use conditions.
1. A method for calibrating and operating one or more systems in an article of active footwear, the active footwear including a lacing engine configured to tighten or relax the footwear in response to a user command at a user input, wherein the user command sets a command signal that controls an operation of the lacing engine based on a relationship between a command signal value of the command signal and a reference value, the method comprising:
receiving a calibration indication; and
in response to receiving the calibration indication:
measuring a present value of the command signal, wherein the present value is based on a first user command at the user input;
providing an updated reference value based on the present value of the command signal;
measuring a subsequent value of the command signal, wherein the subsequent value is based on a subsequent second user command at the user input;
determining whether a transient portion of the command signal, corresponding to the subsequent value of the command signal, indicates a valid input signal or a ground effect type fault condition; and
in absence of the ground effect type fault condition, controlling the lacing engine based on a relationship between the subsequent value of the command signal and the updated reference value.
2. The method of claim 1 , wherein the receiving the user command or receiving the subsequent user command includes receiving information about a presence of a user body at a sensor that is coupled to the active footwear.
3. The method of claim 2 , wherein the receiving the information about the presence of the user body includes receiving information about a presence of a foot inside of the active footwear.
4. The method of claim 1 , wherein the receiving the user command or receiving the subsequent user command includes receiving information about a proximity of a foot to a foot presence sensor inside the article of active footwear.
5. The method of claim 1 , wherein the controlling the lacing engine based on a relationship between the subsequent value of the command signal and the updated reference value includes determining a magnitude difference between the subsequent value of the command signal and the updated reference value, and controlling the lacing engine based on the magnitude difference.
6. The method of claim 1 , wherein the receiving the calibration indication includes receiving the calibration indication from the user via a hardware interface coupled to the lacing engine or via a software interface in a remote device that is in data communication with the lacing engine.
7. The method of claim 1 , wherein the receiving the calibration indication includes receiving the calibration indication from a processor circuit, wherein the processor circuit is configured to provide the calibration indication periodically or according to a specified calibration schedule.
8. The method of claim 1 , wherein the receiving the calibration indication includes receiving the calibration indication from a processor circuit, wherein the processor circuit is configured to provide the calibration indication in response to a detected change in a moisture content of the active footwear.
9. The method of claim 1 , wherein the receiving the calibration indication includes receiving the calibration indication from a processor circuit, wherein the processor circuit is configured to provide the calibration indication in response to a detected use pattern of the active footwear.
10. The method of claim 1 , wherein the receiving the calibration indication includes receiving the calibration indication from a processor circuit, wherein the processor circuit is configured to provide the calibration indication in response to a compression or expansion of a structural component of the active footwear.
11. The method of claim 1 , wherein the receiving the calibration indication includes receiving the calibration indication from a processor circuit, wherein the processor circuit is configured to provide the calibration indication in response to a detected presence of a user body inside of the active footwear when the footwear is relaxed or unconstrained.
12. The method of claim 1 , wherein the updating the reference value includes setting the updated reference value at the same value as the measured present value of the command signal.
13. The method of claim 1 , wherein the measuring the present value of the command signal includes measuring a capacitance value from a capacitive sensor in the active footwear, wherein the capacitive sensor provides the command signal based on a detected presence, absence, or proximity of a user body to the sensor.
14. The method of claim 1 , wherein determining whether the portion of the command signal indicates a valid input signal or a ground effect type fault condition includes:
comparing an amplitude of the subsequent value of the command signal with a reference amplitude, and
comparing an amplitude change characteristic of the portion of the command signal with a reference amplitude change characteristic.
15. The method of claim 1 , wherein determining whether the portion of the command signal indicates a valid input signal includes determining whether the subsequent value of the command signal corresponds to a footwear donning event or the ground effect type fault condition.
16. An article of active footwear comprising:
a user input configured to receive a user command and, in response, provide a command signal representative of the user command;
a lacing engine configured to tighten or relax the footwear based on a relationship between a value of the command signal and a reference value; and
a processor circuit configured to:
receive a calibration indication;
in response to the received calibration indication, measure a present value of the command signal and provide an updated reference value, for use by the lacing engine, based on the present value of the command signal;
receive a subsequent user command at the user input and, in response, measure a subsequent value of the command signal;
determine that an input fault condition exists when a maximum amplitude value of a transient portion of the command signal is less than a specified reference amplitude value and a rise time duration of the transient portion is less than a specified reference rise time, wherein the transient portion of the command signal corresponds in time with receiving the subsequent user command at the user input; and
control the lacing engine based on whether the fault condition exists or does not exist.
17. The article of active footwear of claim 16 , wherein the user input comprises a sensor configured to detect a presence or absence of a user body in proximity to the sensor.
18. The article of active footwear of claim 16 , wherein the user input comprises a capacitive foot presence sensor configured to detect a presence or absence of a user foot inside of the footwear.
19. The article of active footwear of claim 16 , wherein the processor circuit is configured to receive the calibration indication from one or more of:
a hardware interface coupled to the lacing engine;
a software interface in a remote device that is in data communication with the lacing engine;
a clock circuit configured to provide the calibration indication periodically or according to a specified calibration schedule;
a moisture sensor configured to provide the calibration indication in response to a change in a moisture content of the footwear;
an activity sensor configured to provide the calibration indication in response to a detected use pattern of the active footwear; and
a material sensor configured to provide the calibration indication in response to a detected compression or expansion of a structural component of the active footwear.
20. The article of active footwear of claim 16 , wherein in absence of the fault condition, the processor circuit is configured to control the lacing engine based on a relationship between the subsequent value of the command signal and the updated reference value.
21. An article of active footwear comprising:
a footwear engine configured to control a fit of the article of active footwear; and
a processor circuit configured to:
measure a present value of a command signal at a user input and provide an updated reference value based on the present value of the command signal;
receive a subsequent user command at the same user input and, in response, measure a subsequent value of the command signal;
determine, based on a transient portion of the command signal, whether a ground effect type fault condition exists at the user input; and
in absence of the ground effect type fault condition, control the footwear engine based on a relationship between the subsequent value of the command signal and the updated reference value.
22. The article of active footwear of claim 21 , wherein the user input comprises a sensor configured to detect a presence or absence of a user body in proximity to the sensor.
23. The article of active footwear of claim 22 , wherein the sensor is disposed inside of the article of active footwear.
24. The article of active footwear of claim 21 , wherein the user input comprises a capacitive foot presence sensor configured to detect a presence or absence of a user foot inside of the footwear.
25. The article of active footwear of claim 21 , wherein the processor circuit is configured to control the lacing engine based on a magnitude difference between the subsequent value of the command signal and the updated reference value.
26. The article of active footwear of claim 21 , further comprising a motion sensor;
wherein the processor circuit is configured to determine a motion or orientation characteristic of the article of active footwear using information from the motion sensor; and
wherein the processor circuit is configured to control the footwear engine based on a relationship between the subsequent value of the command signal, the updated reference value, and the motion or orientation characteristic as-determined.
27. The article of active footwear of claim 21 , wherein the processor circuit is configured to determine the ground effect type fault condition exists when the transient portion of the command signal has a maximum amplitude characteristic that is less than a maximum reference amplitude value and has a rise time characteristic that is less than a reference rise time duration.
28. The article of active footwear of claim 27 , wherein the maximum reference amplitude value and/or the reference rise time duration is based on previously-received information from the user input about donning or doffing of the article of active footwear.