Always-on shock and orientation detection
The present disclosure is directed to shock and orientation detection for an electronic device. The shock detection detects shock events, such as an accidental drop of the device, and the orientation detection detects the orientation of the device at the time of the detected shock event. The detected shock event and orientations are stored in non-volatile memory. The shock and orientation detection are implemented in low power hardware without any host intervention, and may be implemented as an always-on feature that executes even when the device is in an off or low power state.
1 . A device, comprising:
a first memory;
a second memory;
an accelerometer configured to generate acceleration measurements;
a gyroscope configured to generate angular velocity measurements; and
one or more processors configured to:
determine the device is in a stationary state or a motion state based on the acceleration measurements;
perform orientation detection to detect orientations of the device based on the acceleration measurements and the angular velocity measurements in case the device is determined to be in the motion state;
store the orientations of the device in the first memory;
perform shock detection to detect a shock event based on the acceleration measurements in case the device is determined to be in the motion state, the shock event indicating the device has experienced an impact; and
move the orientations of the device from the first memory to the second memory in case the shock event is detected.
2 . The device of claim 1 wherein the first memory stores the orientations of the device using a first-in, first-out (FIFO) method.
3 . The device of claim 1 wherein the second memory is a non-volatile memory.
4 . The device of claim 1 , further comprising:
a multi-sensor device including the accelerometer, the gyroscope, and the first memory.
5 . The device of claim 1 wherein the one or more processors are configured to:
delete the orientations of the device from the first memory after the orientations have been moved from the first memory to the second memory.
6 . The device of claim 1 wherein the one or more processors are configured to:
set the gyroscope and the shock detection to an off state in case the device is determined to be in the stationary state.
7 . The device of claim 1 wherein the one or more processors are configured to:
set the gyroscope, the shock detection, and the orientation detection to an off state in case the device is determined to be in the stationary state.
8 . The device of claim 1 wherein the one or more processors are configured to:
filter the acceleration measurements;
determine a norm of the filtered acceleration measurements; and
determine the device is in the stationary state or the motion state based on the norm of the filtered acceleration measurements.
9 . The device of claim 8 wherein the acceleration measurements are filtered with a high pass filter.
10 . The device of claim 8 wherein the one or more processors determine the device is in the motion state in case the norm of the filtered acceleration measurements is greater than or equal to a threshold value for a first determined amount of time, and determines the device is in the stationary state in case the norm of the filtered acceleration measurements is less than the threshold value for a second determined amount of time.
11 . The device of claim 1 wherein the one or more processors are configured to:
determine a norm of the acceleration measurements; and
detect the shock event based on the norm of the acceleration measurements.
12 . The device of claim 11 wherein the one or more processors detect the shock event in case the norm of the acceleration measurements is greater than or equal to a threshold value.
13 . The device of claim 1 wherein accelerometer has a first power consumption and measures acceleration at a first rate in case the device is determined to be in the stationary state, and the accelerometer has a second power consumption greater than the first power consumption and measures acceleration at a second rate higher than the first rate in case the device is determined to be in the motion state.
14 . The device of claim 1 wherein the one or more processors include:
a first processor configured to determine the device is in the stationary state or the motion state, perform the orientation detection, store the orientations of the device in the first memory, and perform the shock detection; and
a second processor configured to move the orientations of the device from the first memory to the second memory.
15 . A method, comprising:
generating, by an accelerometer, acceleration measurements;
determining, by a processor, a device is in a stationary state or a motion state based on the acceleration measurements;
generating, by a gyroscope, angular velocity measurements in case the device is determined to be in the motion state;
performing, by the processor, orientation detection to detect orientations of the device based on the acceleration measurements and the angular velocity measurements in case the device is determined to be in the motion state;
storing the orientations of the device in a first memory;
performing shock detection to detect a shock event based on the acceleration measurements in case the device is determined to be in the motion state, the shock event indicating the device has experienced an impact; and
moving the orientations of the device from the first memory to a second memory in case the shock event is detected.
16 . The method of claim 15 wherein the storing of the orientations of the device includes storing the orientations of the device in the first memory using a first-in, first-out (FIFO) method.
17 . The method of claim 15 , further comprising:
setting, by the processor, the gyroscope and the shock detection to an off state in case the device is determined to be in the stationary state.
18 . The method of claim 15 , further comprising:
filtering, by the processor, the acceleration measurements;
determining, by the processor, a norm of the filtered acceleration measurements; and
determining, by the processor, the device is in the stationary state or the motion state based on the norm of the filtered acceleration measurements.
19 . A device, comprising:
a multi-sensor device including:
a first memory;
an accelerometer configured to generate acceleration measurements;
a gyroscope configured to generate angular velocity measurements; and
a first processor configured to:
determine the device is in a motion state based on the acceleration measurements;
detect orientations of the device based on the acceleration measurements and the angular velocity measurements in response to the device being determined to be in the motion state;
store the orientations of the device in the first memory; and
detect a shock event based on the acceleration measurements in response to the device being determined to be in the motion state, the shock event indicating the device has experienced an impact;
a second memory; and
a second processor configured to move the orientations of the device from the first memory to the second memory in response to the shock event being detected.
20 . The device of claim 19 wherein the first processor is configured to:
determine the device is in a stationary state based on the acceleration measurements; and
suspend generation of the angular velocity measurements, detection of the orientations, and detection of the shock event in response to the device being determined to be in the stationary state.