METHOD AND SYSTEM FOR DETERMINING WHETHER STEPS HAVE OCCURRED

• US 20140188431A1
• Filed: 10/31/2013
• Published: 07/03/2014
• Est. Priority Date: 11/01/2012
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: HTI IP LLC (Verizon Communications Inc.)
• Inventors: Barfield, James R.
• Granted Patent: US 10,030,993 B2
• Time in Patent Office: Days
• US Class Current: 702/160
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01C 5/06 by using barometric means

Abstract

A filter processes acceleration magnitude signals from an accelerometer device to output spectral content related to walking and running. A device containing the accelerometer determines steps by qualitatively analyzing the processed acceleration signals to determine whether increased acceleration magnitude results from a step impact from running or walking activity. The device may analyze the acceleration signals to determine crossings of an axis at zero magnitude, which crossings typically correspond to a person'"'"'s foot impacting the ground, and may analyze the period between the zero crossings. The step count can indicate whether the device, in a height determination mode, is moving in a vehicle; if analysis of accelerometer signals indicates no stepping or running, but another circuit of the device indicates rapid movement, the device assumes it is moving in a vehicle, and resets a height above ground value to zero upon determining resumption of walking or running activity.

Claims

1. A device for counting steps, comprising:

a processor configured for;

receiving sampled acceleration data from an acceleration measuring means of the device;

determining calculated magnitude acceleration information from the sampled acceleration data;

comparing a measured first half period time value corresponding to the calculated magnitude acceleration information between a negative to positive zero crossing and a succeeding positive to negative zero crossing to a first half period time threshold;

comparing acceleration values corresponding to the calculated magnitude acceleration information occurring within the measured first half period to a first half period magnitude threshold; and

outputting a step signal indicating that a step has occurred if the compared values meet their corresponding thresholds.

2. The device of claim 1 wherein the processor is further configured for:

incrementing a pre step count value when the output step signal indicates that a step has occurred; and

adding the pre step count value to a total step count value when the pre step count value reaches a predetermined number of step counts.

3. The device of claim 1 wherein the determination by the processor of the calculated magnitude acceleration information from the sampled acceleration data includes filtering the acceleration data with a band-pass filter to generate filtered calculated magnitude acceleration information and wherein the processor is configured to use values corresponding to the filtered calculated magnitude acceleration information in the comparisons to the time and magnitude threshold values.

4. The device of claim 3 wherein cutoff frequencies of the band-pass filter bound frequencies corresponding to step activity determined from spectral analysis of step data sets acquired by devices worn by test subjects.

6. The device of claim 1 wherein the comparing of the measured first half period time to the first half period time threshold includes comparing the measured first half period time to a first half period minimum time threshold and to a first half period maximum time threshold.

7. The device of claim 1 wherein the comparing of the first half period magnitude to the first half period threshold includes comparing the measured first half period maximum magnitude to a first half period minimum maximum magnitude threshold and to a first half period maximum maximum magnitude threshold.

10. The device of claim 2 wherein the pre-step-count value is reset if a just-indicated-step did not occur within a predetermined amount of time since an immediately previous step indication

5. The device of method 1, the processor further configured to perform the steps comprising:

comparing a measured second period time of the calculated magnitude acceleration information based on a positive to negative zero crossing and a negative to positive zero crossing to a second half period time threshold; and

comparing a magnitude value occurring within the measured second half period to a second half period magnitude threshold value.

8. The device of claim 5 wherein the comparing of the measured second half period time to the second half period time threshold includes comparing the measured second half period time to a second half period minimum time threshold and to a second half period maximum time threshold.

9. The device of claim 5 wherein the comparing of the determined second half period magnitude to the second half period threshold includes comparing the second half period minimum magnitude to a second half period minimum minimum magnitude threshold and to a second half period maximum minimum magnitude threshold.

11. A device for counting walking steps and running steps, comprising:

a processor configured for;

receiving sampled acceleration data from an acceleration measuring means of the device;

determining a calculated magnitude acceleration value from the acceleration data for each sample;

filtering the magnitude data with a band-pass filter to generate a sinusoidal representation of the sampled acceleration data;

comparing a measured first half period time value of the sinusoidal representation of the sampled acceleration data between a negative to positive zero crossing and a positive to negative zero crossing to a walking first half period time threshold;

comparing acceleration values occurring within the measured first half period to a walking first half period magnitude threshold value;

comparing a measured first half period time value of the sinusoidal representation of the sampled acceleration data between a negative to positive zero crossing and a positive to negative zero crossing to a running first half period time threshold;

comparing acceleration values occurring within the measured first half period to a running first half period magnitude threshold value;

outputting a running step signal indicating that a running step has occurred if the compared values meet their corresponding running threshold values;

outputting a walking step signal indicating that a walking step has occurred if the compared values meet their corresponding walking threshold values.

12. The device of claim 11 wherein the processor is further configured for:

incrementing a pre walking step count when the output walking step signal indicates that a walking step has occurred;

adding the pre walking step count to a total walking step count when the pre walking step count reaches a predetermined number of step counts;

incrementing a pre running step count when the output running step signal indicates that a running step has occurred; and

adding the pre running step count to a total running step count when the pre running step count reaches a predetermined number of running step counts.

13. The device of claim 12 wherein the pre running step count and the pre walking step count are reset if a just-indicated-step did not occur within a predetermined amount of time since an immediately previous step indication.

14. The device of claim 11 wherein the walking first half period time threshold is a walking first half period maximum time threshold, the running first half period time threshold is a running first half period maximum time threshold, and

wherein processor is further configured to compare the measured first half period time value to a walking first half period minimum time threshold and to a running first half period minimum time threshold.

15. The device of claim 11 wherein the processor is further configured for:

comparing a measured second half period time value of the sinusoidal representation of the sampled acceleration data between a positive to negative zero crossing and a negative to positive zero crossing to a walking second half period time threshold;

comparing acceleration values occurring within the measured second half period to a walking second half period magnitude threshold value;

comparing a measured second half period time value of the sinusoidal representation of the sampled acceleration data between a positive to negative zero crossing and a negative to positive zero crossing to a running second half period time threshold;

comparing acceleration values occurring within the measured second half period to the running second half period magnitude threshold value.

16. The device of claim 11 wherein the comparing of the measured first half period time to the walking first half period time threshold includes comparing the measured the first half period time to a walking first half period minimum time threshold, to a first half period maximum time threshold, to a running first half period minimum time threshold, to a running first half period maximum time threshold.

17. The device of claim 11 wherein the processor is further configured to compare the acceleration data between a negative to positive zero crossing and a positive to negative zero crossing to a running first half period minimum time threshold and a running first half period maximum time threshold and comparing the maximum magnitude value occurring within the measured first half period to the running first half period maximum maximum magnitude threshold value and to the running first half period minimum maximum magnitude threshold value.

18. A device for counting walking steps and running steps, comprising:

a processor configured for;

receiving sampled acceleration data from an acceleration measuring means;

determining a calculated magnitude acceleration value from the acceleration data for each sample;

filtering the magnitude data with a band-pass filter;

determining from the filtered magnitude data that a walking step has occurred if a comparison of the filtered magnitude data to predetermined walking step thresholds indicates that a walking step has occurred;

determining from the filtered magnitude data that a running step has occurred if a comparison of the filtered magnitude data to predetermined running step thresholds indicates that a running step has occurred;

outputting a walking step signal indicating that a walking step has occurred if the processor determines that a walking step has occurred; and

outputting a running step signal indicating that a running step has occurred if the processor determine that a running step has occurred.

19. The device of claim 18 wherein the processor is further configured for:

incrementing a pre step count value if the outputted signal indicates that a walking step has occurred; and

adding the pre step count value to a total step count value when the pre step count value reaches a predetermined number of step counts.

20. The device of claim 18 wherein the processor is further configured for:

incrementing a running pre step count value if the outputted signal indicates that a running step has occurred; and

adding the running pre step count value to a total step count value when the running pre step count value reaches a predetermined number of step counts.