Sensor auto-calibration

• US 9,534,924 B2
• Filed: 11/09/2012
• Issued: 01/03/2017
• Est. Priority Date: 11/11/2011
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ahuja, Disha, Kulik, Victor, Puig, Carlos M., Desai, Ashish Nagesh
• Primary Examiner(s): Lee, Paul D
• Application Number:
  US13/673,967
• Publication Number:
  US 20130124127A1
• Time in Patent Office: 1,516 Days
• Field of Search: 702/86, 702/96, 702/104
• US Class Current: 1/1
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01K 15/00 Testing or calibrating of thermometers
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• CPC Class Codes: G06F 1/329 by task scheduling
• CPC Class Codes: G06F 15/00 Digital computers in general details G06F1/00 – G06F13/00; Data processing equipment in general
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Aspects of the disclosure relate to computing technologies. In particular, aspects of the disclosure relate to mobile computing device technologies, such as systems, methods, apparatuses, and computer-readable media to improve the calibration data by taking into account the effects of change in temperature on motion sensors. For instance, different levels of error may be associated with a motion sensor at different temperature levels. In one implementation, the sensor measurement data associated with the various orientations at a temperature is used in determining the calibration data for that temperature.

Claims

1. A method for calibrating a sensor on a mobile device, the method comprising:

detecting, via a temperature sensor coupled to the mobile device, temperature of an operating environment for a sensor coupled to the mobile device;

identifying, via a processor coupled to the mobile device, a temperature bin from a plurality of temperature bins for the sensor using the detected temperature, in response to detecting temperature of an operating environment for the sensor, wherein the temperature bin comprises a range of temperatures, wherein the temperature bin has one or more sensor measurements received at a temperature within the range of temperatures associated with the temperature bin;

determining, via the processor, that diversity among previously stored sensor measurement data at or near the temperature is below a threshold;

in response to determining that the diversity associated with the sensor measurement data at or near the temperature is below the threshold, generating, via the processor, calibration data for the sensor for the detected temperature using sensor measurement data from a previously detected temperature, wherein the generating comprises using sensor measurement data from another temperature bin;

lowering, via the processor, a weight associated with the sensor measurement data from another temperature bin by adjusting one or more parameters of a filter associated with the temperature bin;

calibrating, via the processor and based at least in part on the generated calibration data, output from the sensor at or near the temperature; and

operating, via the processor, the sensor based on the calibrated output.

2. The method of claim 1, wherein the sensor is one or more of an accelerometer, a gyroscope or a magnetometer.

3. The method of claim 1, wherein the generating comprises linearly interpolating sensor measurement data for at least one orientation at the temperature bin for the detected temperature using the sensor measurement data from one or more adjacent temperature bins to an identified temperature bin.

4. The method of claim 3, wherein linearly interpolating sensor measurement data comprises using the sensor measurement from one or more adjacent temperature bins and a pre-determined slope of a change in sensor measurement data with respect to a change in temperature for deriving the sensor measurement data for the at least one orientation at the temperature bin.

5. The method of claim 1, wherein each temperature bin is associated with a respective filter.

6. The method of claim 1, further comprising updating the sensor measurement data for at least one orientation at the detected temperature using the sensor measurement data from another temperature.

7. The method of claim 1, wherein the calibration data comprises a sensor offset or a sensitivity.

8. A mobile device for generating calibration data, comprising:

a temperature sensor configured to detect temperature of an operating environment for a sensor coupled to the mobile device;

a temperature compensation module configured to;

identify a temperature bin from a plurality of temperature bins for the sensor using the detected temperature, in response to detecting temperature of an operating environment for the sensor, wherein the temperature bin comprises a range of temperatures, wherein the temperature bin has one or more sensor measurements received at a temperature within the range of temperatures associated with the temperature bin;

determine that diversity among previously stored sensor measurement data at or near the temperature is below a threshold;

generate calibration data for the sensor for the detected temperature using sensor measurement data from a previously detected temperature, in response to determining that the diversity associated with the sensor measurement data at or near the temperature is below the threshold, wherein the generating comprises using sensor measurement data from another temperature bin;

lower a weight associated with the sensor measurement data from another temperature bin by adjusting one or more parameters of a filter associated with the temperature bin; and

a processor configured to;

calibrate, based at least in part on the generated calibration data, output from the sensor at or near the temperature; and

operate the sensor based on the calibrated output.

9. The mobile device of claim 8, wherein the sensor is one or more of an accelerometer, a gyroscope or a magnetometer.

10. The mobile device of claim 8, wherein the generating comprises linearly interpolating sensor measurement data for at least one orientation at the temperature bin for the detected temperature using the sensor measurement data from one or more adjacent temperature bins to an identified temperature bin.

11. The mobile device of claim 10, wherein linearly interpolating sensor measurement data comprises using the sensor measurement from one or more adjacent temperature bins and a pre-determined slope of a change in sensor measurement data with respect to a change in temperature for deriving the sensor measurement data for the at least one orientation at the temperature bin by the temperature compensation module.

12. The mobile device of claim 8, wherein each temperature bin is associated with a respective filter.

13. The mobile device of claim 8, wherein the temperature compensation module is further configured to update the sensor measurement data for at least one orientation at the detected temperature using the sensor measurement data from another temperature.

14. The mobile device of claim 8, wherein the calibration data comprises a sensor offset or a sensitivity.

15. A non-transitory computer readable storage medium, wherein the non-transitory computer readable storage medium comprises instructions executable by a processor, the instructions comprising instructions to:

detect temperature of an operating environment for a sensor coupled to a mobile device;

identify a temperature bin from a plurality of temperature bins for the sensor using the detected temperature, in response to detecting temperature of an operating environment for the sensor, wherein the temperature bin comprises a range of temperatures, wherein the temperature bin has one or more sensor measurements received at a temperature within the range of temperatures associated with the temperature bin;

determine that diversity among previously stored sensor measurement data at or near the temperature is below a threshold;

generate calibration data for the sensor for the detected temperature using sensor measurement data from a previously detected temperature, in response to determining that the diversity associated with the sensor measurement data at or near the temperature is below the threshold, wherein the generating comprises using sensor measurement data from another temperature bin;

lower a weight associated with the sensor measurement data from another temperature bin by adjusting one or more parameters of a filter associated with the temperature bin;

calibrate, based at least in part on the generated calibration data, output from the sensor at or near the temperature; and

operate the sensor based on the calibrated output.

16. An apparatus, comprising:

means for detecting temperature of an operating environment for a sensor coupled to a mobile device;

means for identifying a temperature bin from a plurality of temperature bins for the sensor using the detected temperature, in response to detecting temperature of an operating environment for the sensor, wherein the temperature bin comprises a range of temperatures, wherein the temperature bin has one or more sensor measurements received at a temperature within the range of temperatures associated with the temperature bin;

means for determining that diversity among previously stored sensor measurement data at or near the temperature is below a threshold;

means for generating calibration data for the sensor for the detected temperature using sensor measurement data from a previously detected temperature, in response to determining that the diversity associated with the sensor measurement data at or near the temperature is below the threshold, wherein the generating comprises using sensor measurement data from another temperature bin;

means for lowering a weight associated with the sensor measurement data from another temperature bin by adjusting one or more parameters of a filter associated with the temperature bin;

means for calibrating, based at least in part on the generated calibration data, output from the sensor at or near the temperature; and

means for operating the sensor based on the calibrated output.

17. The apparatus of claim 16, wherein the generating comprises means for linearly interpolating sensor measurement data for at least one orientation at the temperature bin for the detected temperature using the sensor measurement data from one or more adjacent temperature bins to an identified temperature bin.

18. The apparatus of claim 17, wherein linearly interpolating sensor measurement data comprises using the sensor measurement from one or more adjacent temperature bins and a pre-determined slope of a change in sensor measurement data with respect to a change in temperature for deriving the sensor measurement data for the at least one orientation at the temperature bin.

19. The apparatus of claim 16, wherein each temperature bin is associated with a respective filter.

20. The apparatus of claim 16, further comprising means for updating the sensor measurement data for at least one orientation at the detected temperature using the sensor measurement data from another temperature.

21. The apparatus of claim 16, wherein the calibration data comprises a sensor offset or a sensitivity.