METHOD AND SYSTEM FOR DETERMINING THE HEIGHT OF A DEVICE ABOVE GROUND

• US 20140172351A1
• Filed: 12/18/2012
• Published: 06/19/2014
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: HTI IP LLC (Verizon Communications Inc.)
• Original Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Inventors: Taylor, Tom, Barfield, James
• Granted Patent: US 9,939,264 B2
• Time in Patent Office: Days
• US Class Current: 702/138
• CPC Class Codes: G01C 5/06 by using barometric means
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A device updates a value representing its current height above ground when it detects a height change. The device uses the slope calculated from collected barometric pressure data samples to calculate height change during a period when the value of the slope exceeds a predetermined value. The device also analyzes a predetermined number of barometric pressure sensor data samples preceding and succeeding a height change indicated by the slope change. The device performs an evaluation, i.e., determining the difference between an average of the preceding and succeeding samples, to determine a height change. The device may select either the slope-of-the-curve-during-the-height-change-period method or the difference-between-the-averages method based on meeting a criterion. The processor de-energizes a GPS circuit, height determination method, and sets the height above ground to zero if it detects movement. Placing the device on a charger resets the device'"'"'s height value to the charger height above ground.

Claims

1. A device having a processor for determining the height above ground, the processor configured for performing the steps comprising:

receiving barometric pressure data samples from a barometric pressure sensor;

evaluating the barometric pressure data samples to determine a slope of a best fit line that represents a change in height of the device between a current sample time and one, or more, previous sample times; and

applying a value representing the slope to a previously determined current height value of the device.

2. The device of claim 1 further comprising a movement determination component, wherein the processor is further configured for:

requesting a movement information value corresponding to movement of the device from the movement determination component,

receiving the movement information value from the movement determination component in response to the request for same if the movement determination component can determine movement;

comparing the received movement information value to a predetermined movement criterion; and

setting to zero the previously determined current height value if the received movement information value exceeds the predetermined movement criterion.

3. The device of claim 2 wherein the processor is further configured to enter a wait state for a predetermined period if the received movement information value exceeds the predetermined movement criterion.

4. The device of claim 2 wherein the movement determination component includes GPS circuitry.

5. The device of claim 2 wherein the movement information value corresponds to the speed of the device.

6. The device of claim 1 wherein the determined slope is compared to a first criterion for movement in an ascending direction and a second criterion for movement in a descending direction.

7. The device of claim A wherein the slope is compared to a predetermined criterion and added to the previously determined current height value of the device if the slope exceeds the predetermined criterion.

8. The device of claim 7 wherein the predetermined criterion is selected to represent a value greater than noise of the device.

9. The device of claim 7 wherein the predetermined criterion is selected so that the slope will not exceed the predetermined criterion when the slope results from barometric pressure changes due to reasons other than moving between floors in a building.

10. A device having a processor for determining the height above ground, the processor configured for performing the steps comprising:

receiving data corresponding to barometric pressure data samples from a barometric pressure sensor into a first memory;

evaluating the data corresponding to the barometric pressure, data samples to determine whether a slope of the data corresponding to the barometric pressure data samples exceeds a predetermined first slope threshold indicating a first change in slope;

storing the data from the first memory to a second memory when the slope of the data corresponding to the barometric pressure data samples does not exceed a predetermined second slope threshold indicating a second change in slope;

evaluating the data corresponding to the barometric pressure data samples stored in the first and second memories to determine that a change in height of the device has occurred during a period between the occurrences of the first and second changes in slope; and

applying a value corresponding the determined change in height to a previously determined current height value.

11. The device of claim 10 wherein the predetermined first slope threshold equals the predetermined second slope threshold.

12. The device of claim 10 further comprising a movement determination component, wherein the processor is further configured for:

requesting a movement information value corresponding to movement of the device from the movement determination component,

receiving the movement information value from the movement determination component in response to the request for same if the movement determination component can determine movement;

comparing the received movement information value to a predetermined movement criterion; and

setting to zero the previously determined current height value if the received movement information value exceeds the predetermined movement criterion.

13. The device of claim 12 wherein the processor is further configured to enter a wait state for a predetermined period it the received movement information value exceeds the predetermined movement criterion.

14. The device of claim 12 wherein the predetermined movement criterion corresponds to a predetermined speed substantially along the Earth'"'"'s surface.

15. The device of claim 12 wherein the processor is further configured for placing the movement information component into a low power state if the received movement information value exceeds the predetermined movement criterion.

16. A device having a processor for determining the height above ground, the processor configured for performing the steps comprising:

receiving barometric pressure data samples from a barometric pressure sensor into a first memory;

evaluating the barometric pressure data samples to determine a slope of the barometric pressure data samples;

comparing the determined slope to a predetermined slope criterion;

storing samples stored in the first memory into a second memory when the determined slope exceeds the predetermined slope criterion indicating a first change in slope;

determining an offset value based on the determined slope and sample rate that the first memory receives the barometric pressure data samples;

determining whether the offset value exceeds a predetermined offset threshold value;

adding the offset value to a current height value if the offset value exceeds the predetermined offset threshold value; and

if the offset value does not exceed the predetermined offset threshold value;

storing the received barometric data from the first memory to a third memory if the evaluation of the barometric pressure data samples indicates that a second change in slope has occurred;

evaluating the barometric pressure data samples stored in the second and third memories to determine that a change in height of the device has occurred during a period between the occurrences of the first and second changes in slope; and

adding a value corresponding the change in height determined from the first and second changes in slope to the current height value.

17. The device of claim 16 wherein the evaluation of the data samples in the second and third memories includes:

averaging each of the memories and subtracting one average from the other to determine the change in height.

18. The device of claim 16 further comprising a movement determination component, wherein the processor is further configured for:

requesting a movement information value corresponding to movement of the device from the movement determination component;

receiving the movement information value from the movement determination component in response to the request for same if the movement determination component can determine movement;

comparing the received movement information value to a predetermined movement criterion; and

setting to zero the previously determined current height value if the received movement information value exceeds the predetermined movement criterion.

19. The device of claim 18 wherein the processor is further configured to enter a wait state for a predetermined period if the received movement information value exceeds the predetermined movement criterion.

20. The device of claim 18 wherein the movement determination component device includes global positioning circuitry for indicating that at least one of a latitude or longitude coordinate has changed.