Mitigating the effect of a change in sensor calibration parameters

Patent metadata

Field	Value
Publication number	US-9625490-B2
Application number	US-201213418741-A
Country	US
Kind code	B2
Filing date	Mar 13, 2012
Priority date	Dec 1, 2011
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

The disclosure relates to mitigating the effect of a sudden change in sensor calibration parameters. An embodiment of the disclosure retrieves a current calibration parameter value for the sensor, determines a new calibration parameter value for the sensor, and generates transitional calibration parameter values based at least on the current calibration parameter value and the new calibration parameter value using an interpolation function configured to prevent a sudden change in the sensor calibration parameter values.

First claim

What is claimed is:

1. A method for calibrating a sensor in a wireless device, comprising:
retrieving, at the wireless device, a current calibration parameter value for the sensor, wherein the current calibration parameter value is a scale factor value or an axis non-orthogonality value;
determining, at the wireless device, a new calibration parameter value for the sensor;
generating, at the wireless device, one or more transitional calibration parameter values for the sensor based on at least the current calibration parameter value and the new calibration parameter value using interpolation logic configured to prevent a sudden change in a stream of calibrated sensor data;
generating, at the wireless device, a stream of raw sensor data by using the sensor to measure a local environment of the wireless device; and
generating, at the wireless device, the stream of calibrated sensor data based on the stream of raw sensor data, the current calibration parameter value, the one or more transitional calibration parameter values, and the new calibration parameter value,
wherein the generating the stream of calibrated sensor data comprises:
generating a stream of transitional calibrated sensor data based on the stream of raw sensor data generated during a transition time and the one or more transitional calibration parameter values; and
generating a stream of new calibrated sensor data based on the stream of raw sensor data generated subsequent to the transition time and the new calibration parameter value.

2. The method of claim 1 , wherein the interpolation logic includes a linear interpolation function.

3. The method of claim 1 , wherein the interpolation logic includes a non-linear interpolation function.

4. The method of claim 1 , further comprising:
establishing the new calibration parameter value as the current calibration parameter value after a predetermined time.

5. The method of claim 1 , further comprising:
establishing the new calibration parameter value as the current calibration parameter value after completion of the interpolation logic.

6. The method of claim 1 , further comprising:
transitioning from the current calibration parameter value to the new calibration parameter value by outputting the one or more transitional calibration parameter values.

7. The method of claim 6 , wherein the transitioning comprises transitioning from the current calibration parameter value to the new calibration parameter value in real-time.

8. The method of claim 6 , further comprising:
changing an amount of time of the transition time,
wherein the transitioning comprises transitioning from the current calibration parameter value to the new calibration parameter value over the changed transition time, to improve performance of the sensor calibration.

9. The method of claim 1 , further comprising:
timestamping the new calibration parameter value,
wherein the transitioning comprises transitioning from the current calibration parameter value to the new calibration parameter value in a post-processing mode.

10. The method of claim 1 , further comprising:
retrieving a previous set of current and new calibration parameter values for the sensor,
wherein the generating the one or more transitional calibration parameter values comprises generating the one or more transitional calibration parameter values based on the previous set of current and new calibration parameter values, the current calibration parameter value, and the new calibration parameter value using multi-point interpolation logic configured to prevent the sudden change in the stream of calibrated sensor data.

11. An apparatus for calibrating a sensor in a wireless device, comprising:
means for retrieving a current calibration parameter value for the sensor, wherein the current calibration parameter value is a scale factor value or an axis non-orthogonality value;
means for determining a new calibration parameter value for the sensor;
means for generating one or more transitional calibration parameter values for the sensor based on at least the current calibration parameter value and the new calibration parameter value using interpolation logic configured to prevent a sudden change in a stream of calibrated sensor data;
means for generating a stream of raw sensor data by using the sensor to measure a local environment of the wireless device; and
means for generating the stream of calibrated sensor data based on the stream of raw sensor data, the current calibration parameter value, the one or more transitional calibration parameter values, and the new calibration parameter value,
wherein the means for generating the stream of calibrated sensor data
generates a stream of transitional calibrated sensor data based on the stream of raw sensor data generated during a transition time and the one or more transitional calibration parameter values, and
generates a stream of new calibrated sensor data based on the stream of raw sensor data generated subsequent to the transition time and the new calibration parameter value, and

wherein the apparatus is hardware or a combination of hardware and software.

12. A wireless device, comprising:
logic configured to retrieve a current calibration parameter value for a sensor in the wireless device, wherein the current calibration parameter value is one of a scale factor value or an axis non-orthogonality value;
logic configured to determine a new calibration parameter value for the sensor;
logic configured to generate one or more transitional calibration parameter values for the sensor based on at least the current calibration parameter value and the new calibration parameter value using interpolation logic configured to prevent a sudden change in a stream of calibrated sensor data;
logic configured to generate a stream of raw sensor data by using the sensor to measure a local environment of the wireless device; and
logic configured to generate the stream of calibrated sensor data based on the stream of raw sensor data, the current calibration parameter value, the one or more transitional calibration parameter values, and the new calibration parameter value,
wherein the logic configured to generate the stream of calibrated sensor data
is configured to generate a stream of transitional calibrated sensor data based on the stream of raw sensor data generated during a transition time and the one or more transitional calibration parameter values, and
is configured to generate a stream of new calibrated sensor data based on the stream of raw sensor data generated subsequent to the transition time and the new calibration parameter value.

13. The wireless device of claim 12 , wherein the interpolation logic includes a linear interpolation function.

14. The wireless device of claim 12 , wherein the interpolation logic includes a non-linear interpolation function.

15. The wireless device of claim 12 , further comprising:
logic configured to establish the new calibration parameter value as the current calibration parameter value after a predetermined time.

16. The wireless device of claim 12 , further comprising:
logic configured to establish the new calibration parameter value as the current calibration parameter value after completion of the interpolation logic.

17. The wireless device of claim 12 , further comprising:
logic configured to transition from the current calibration parameter value to the new calibration parameter value by outputting the one or more transitional calibration parameter values.

18. The wireless device of cla

Assignees

• Czompo Joseph
• Qualcomm Inc

Inventors

• Czompo Joseph

Classifications

• G01C25/00

  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 title

• G01C25/005

  initial alignment, calibration or starting-up of inertial devices · CPC title

• G01D3/032

  affecting incoming signal, e.g. by averaging; gating undesired signals · CPC title

• G01D18/00

  Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00 · CPC title

• G01P21/00 Primary

  Testing or calibrating of apparatus or devices covered by the preceding groups · CPC title