Systems and methods for determining when to calibrate a pressure sensor of a mobile device

Patent metadata

Field	Value
Publication number	US-12298196-B2
Application number	US-202318342536-A
Country	US
Kind code	B2
Filing date	Jun 27, 2023
Priority date	May 24, 2018
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

A method involves determining weighted metric values for each metric of a plurality of metrics by applying a weight for each metric to a determined value of each metric. The method further involves using the weighted metric values to determine if a pressure sensor of a mobile device should be calibrated using information associated with the first location, and if a determination is made that the pressure sensor of the mobile device should be calibrated using information associated with the first location, then using the information associated with the first location to calibrate the pressure sensor of the mobile device.

First claim

The invention claimed is:

1. A method, comprising:
for each metric of a plurality of metrics, determining a weighted metric value by applying a weight for that metric to a determined value of that metric;
using the weighted metric values to determine if a pressure sensor of a mobile device should be calibrated using information associated with a first location; and
if the pressure sensor of the mobile device should be calibrated using the information associated with the first location, using the information associated with the first location to calibrate the pressure sensor of the mobile device.

2. The method of claim 1 , wherein using the weighted metric values to determine if a pressure sensor of a mobile device should be calibrated using information associated with a first location comprises:
using the weighted metric values to determine a quality of an opportunity to calibrate the pressure sensor of the mobile device using a measurement of pressure of the first location that was measured by the pressure sensor; and
determining if the determined quality of the opportunity to calibrate exceeds a threshold quality value,
wherein the information includes the measurement of pressure and the pressure sensor of the mobile device is calibrated using the measurement of pressure if the determined quality of the opportunity to calibrate exceeds the threshold quality value.

3. The method of claim 1 , wherein if the pressure sensor of the mobile device should not be calibrated using the information associated with the first location, the method further comprises:
for each metric of the plurality of metrics, determining a new value of that metric based on how data collected at a second location of the mobile device relates to a threshold condition of that metric;
for each metric of the plurality of metrics, determining a new weighted metric value by applying the weight for that metric, or a new weight for that metric, to the determined new value of that metric;
using the new weighted metric values to determine if the pressure sensor of the mobile device should be calibrated using information associated with the second location; and
if the pressure sensor of the mobile device should be calibrated using the information associated with the second location, using the information associated with the second location to calibrate the pressure sensor of the mobile device.

4. The method of claim 1 , wherein determining a weighted metric value by applying the weight for that metric to the metric comprises:
determining the weighted metric value by multiplying the value of that metric and the weight.

5. The method of claim 1 , wherein the information associated with the first location includes a measurement of pressure at the first location that was measured by the pressure sensor, and an altitude value associated with the first location.

6. The method of claim 5 , the altitude value associated with the first location includes a known altitude of a specific position or flat area.

7. The method of claim 5 , the altitude value associated with the first location includes a representative altitude of a non-flat area.

8. The method of claim 1 , wherein one of the metrics represents whether altitudes of the first location meet a threshold altitude variation condition.

9. The method of claim 1 , wherein one of the metrics represents whether the first location is likely to be in a building or vehicle in which an HVAC effect or stack/chimney effect is present, or in a vehicle in which another pressure variation condition is present.

10. The method of claim 1 , wherein one of the metrics represents whether the first location is likely to be at a ground floor of a building, outside at a known ground altitude, or within a range of altitudes.

11. The method of claim 1 , wherein one of the metrics represents whether measured satellite signal strengths for signals from different satellites are above a threshold strength value that indicates the first location is likely to be outside at a known ground altitude or within a range of altitudes.

12. The method of claim 1 , wherein one of the metrics represents whether an estimated altitude is above a threshold altitude that indicates the first location is likely to be inside a building and not at a known ground altitude or within a range of altitudes.

13. The method of claim 1 , wherein one of the metrics represents whether an internal temperature of the mobile device is at a level of temperature that can impact an accuracy of a pressure measurement by the pressure sensor.

14. The method of claim 1 , wherein one of the metrics represents whether a type of movement of the mobile device is conducive or not conducive for calibrating the pressure sensor.

15. The method of claim 1 , wherein one of the metrics represents whether a threshold amount of time has passed since the pressure sensor was last calibrated according to calibration records stored on the mobile device or a location remote from the mobile device.

16. The method of claim 15 , wherein the weight for the metric representing whether a threshold amount of time has passed since the pressure sensor was last calibrated is greater than weights for other metrics of the plurality of metrics.

17. The method of claim 1 , wherein a first weight for a first metric of the plurality of metrics is greater than a second weight of a second metric of the plurality of metrics, wherein the first metric represents whether a threshold amount of time has passed since the pressure sensor was last calibrated.

18. The method of claim 1 , wherein the plurality of metrics include two or more metrics from the following: a metric representing whether altitudes of the first location meet a threshold altitude variation condition; a metric representing whether the first location is likely to be in a building or vehicle in which an HVAC effect or stack/chimney effect is present, or in a vehicle in which another pressure variation condition is present; a metric representing whether the first location is likely to be outside at a known ground altitude or within a range of altitudes; a metric representing whether measured satellite signal strengths for signals from different satellites are above a threshold strength value that indicates the first location is likely to be outside at a known ground altitude or within a range of altitudes; a metric representing whether an estimated altitude is above a threshold altitude that indicates the first location is likely to be inside a building and not at a known ground altitude or within a range of altitudes; a metric representing whether an internal temperature of the mobile device is at a level of temperature that can impact an accuracy of a pressure measurement by the pressure sensor; a metric representing whether a type of movement of the mobile device is conducive or not conducive for calibrating the pressure sensor; and a metric representing whether a threshold amount of time has passed since the pressure sensor was last calibrated according to calibration records stored on the mobile device or a location remote from the mobile device.

19. One or more non-transitory machine-readable media embodying program instructions that, when executed by one or more machines, cause the one or more machines to implement the method of claim 1 .

20. A system for determining when to calibrate a pressure sensor of a mobile device, the system comprising one or more machines configured to perform the method of claim 1 .

Assignees

• Nextnav Llc

Inventors

• Dormody Michael
• Han Guiyuan
• Nagarajan Badrinath

Classifications

• G01L19/00

  Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges · CPC title

• G01C21/206

  specially adapted for indoor navigation · CPC title

• G01L27/002

  Calibrating, i.e. establishing true relation between transducer output value and value to be measured, zeroing, linearising or span error determination · CPC title

• G01C5/06

  by using barometric means · CPC title

• G01L27/005 Primary

  Apparatus for calibrating pressure sensors · CPC title