METHODS AND ARCHITECTURE FOR DETERMINING ACTIVITY AND ACTIVITY TYPES FROM SENSED MOTION SIGNALS
Embodiments of the invention relate generally to electrical and electronic hardware, computer software, wired and wireless network communications, and wearable computing devices for facilitating health and wellness-related information. More specifically, disclosed are systems, methods, devices, computer readable medium, and apparatuses configured to determine activity and activity types, including gestures, from sensed motion signals using, for example, a wearable device (or carried device) and one or more motion sensors. In at least some embodiments, an apparatus can include a wearable housing, and a motion sensor configured to generate a motion sensor signal. The apparatus also may include a motion processor configured to generate intermediate motion signals from the motion sensor signal, and an activity processor configured to identify an activity based on the intermediate motion signals.
1 . An apparatus comprising:
a wearable housing;
a motion sensor configured to sense motion associated with the wearable housing and to generate a motion sensor signal;
a motion processor configured to generate intermediate motion signals from the motion sensor signal; and
an activity processor configured to identify an activity based on the intermediate motion signals.
2 . The apparatus of claim 1 , wherein the motion processor includes:
an intermediate motion signal generator; and
a motion characteristic identifier.
3 . The apparatus of claim 2 , wherein the intermediate motion signal generator is configured to decompose the motion sensor signal into decomposed signals.
4 . The method of claim 3 , wherein the intermediate motion signal generator is further configured to:
generate a decomposed signal using one or more estimators.
5 . The apparatus of claim 3 , wherein the motion characteristic is configured to extract features from the decomposed signals.
6 . The apparatus of claim 5 , wherein the motion characteristic is further configured to:
form signals representing one or more of an orientation, an applied acceleration, and a centripetal acceleration based on the decomposed signals; and
extract features from the signals representing one or more of the orientation, the applied acceleration, and the centripetal acceleration based on one or more wavelet transformations.
7 . The apparatus of claim 1 , further comprising:
an in-line auto-calibrator configured to recalibrate the motion sensor signal in-situ to form a calibrated motion signal, the in-line auto-calibrator configured further to generate the calibrated motion signal.
8 . The apparatus of claim 7 , wherein the in-line auto-calibrator is further configured to:
determine a power spectral density based on the motion sensor signal;
subtract an average value of a DC frequency bin from a value of the DC frequency bin to determine a remaining value associated with other frequency bins; and
obtain a root mean square (“RMS”) value of the remaining value.
9 . The apparatus of claim 1 , further comprising:
a sample rate controller configured to modify the sample rate of the motion sensor signal to form an adjusted sample rate with which to sample the motion sensor signal.
10 . The apparatus of claim 9 , wherein the sample rate controller is configured to:
receive usage data from the activity processor indicating a level of activity; and
generate control data to modify the sample rate responsive to the level of activity.
11 . The apparatus of claim 1 , wherein the motion processor includes a digital signal processing core and the activity processor includes a microcontroller core.
12 . The apparatus of claim 1 , wherein the motion sensor comprises:
one or more accelerometers.
13 . A method comprising:
receiving data representing a motion sensor signal from a motion sensor disposed in a housing of a wearable device;
generating intermediate motion signals based on the motion sensor signal, the intermediate motion signals including one or more decomposed signals; and
identifying an activity based on the intermediate motion signals.
14 . The method of claim 13 , wherein receiving the data representing the motion sensor signal from the motion sensor further comprises:
receiving accelerometer data representing an acceleration signal from an accelerometer.
15 . The method of claim 13 , further comprising:
determining the wearable device is in a still state;
calibrating the motion sensor signal in-situ to form a calibrated motion signal.
16 . The method of claim 13 , further comprising:
monitoring a spectrum associated with the motion sensor signal; and
modifying a sample rate of the motion sensor signal to form an adjusted sample rate based on an amount of energy associated with the spectrum.
17 . The method of claim 13 , wherein generating the intermediate motion signals including the one or more decomposed signals comprises:
generating the one or more decomposed signals using one or more estimators.
18 . The method of claim 13 , wherein generating the intermediate motion signals including the one or more decomposed signals comprises:
forming signals representing one or more of an orientation, an applied acceleration, and a centripetal acceleration.
19 . The method of claim 13 , further comprising:
identifying characteristics of motion based on the intermediate motion signals to form motion characteristics data
20 . The method of claim 19 , wherein identifying the characteristics of motion comprises:
forming signals representing one or more of an orientation, an applied acceleration, and a centripetal acceleration based on the one or more decomposed signals; and
applying one or more wavelet transformations to extract features from the signals representing one or more of the orientation, the applied acceleration, and the centripetal acceleration.