Device and method of gyro sensor calibration

• US 20120116716A1
• Filed: 11/08/2011
• Published: 05/10/2012
• Est. Priority Date: 11/08/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Anatole M. Lokshin
• Inventors: Lokshin, Anatole M., Kuzkin, Vitaly, Dvas, Nikolay
• Granted Patent: US 9,146,134 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: G01C 17/38 Testing, calibrating, or compensating of compasses
• CPC Class Codes: G01C 19/00 Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• 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

Abstract

Embodiments of the present disclosure are directed to a method and apparatus for calibration of gyro sensors by using magnetic sensor measurements and background computation during normal product operation. In one embodiment, magnetic sensor measurements are used to adjust gyro gain by comparing measured magnetic vector orientation with its expected orientation computed from gyro integration. The background process constantly compares this discrepancy for various values of gyro gain and selects the one that minimizes such error on average. In one embodiment, device orientation obtained by gyro integration is improved by using magnetic sensor measurements.

Claims

1-20. -20. (canceled)

21. An electronic device comprising:

a microprocessor communicating with a memory;

a gyroscopic sensor for determining a rotational position of the electronic device;

a stored gain parameter that is adapted to be applied to gyroscopic sensor data produced by the gyroscopic sensor;

a magnetic sensor for determining the rotational position of the electronic device; and

the memory storing instructions configured to instruct the microprocessor to perform operations as part of a feedback process, the operations comprising;

integrating a time-series set of gyroscopic sensor data associated with a period of time from the gyroscopic sensor;

measuring a time-series set of magnetic sensor data associated with the period of time from the magnetic sensor;

comparing the integrated gyroscopic sensor data from the period of time with the magnetic sensor data from the period of time to create an error measure for the period of time;

determining an updated gyroscopic sensor gain parameter based on the error measure; and

adjusting the stored gyroscopic sensor gain parameter to the updated gyroscopic sensor gain parameter.

22. The electronic device of claim 21, wherein the stored gyroscopic sensor gain parameter is a first stored gyroscopic sensor gain parameter of a plurality of stored gyroscopic sensor gain parameters, wherein the circuitry is further adapted to perform:

integrating the time-series of gyroscopic sensor data using each of the plurality of stored gyroscopic sensor gain parameters to create a plurality of gain-adjusted integrated gyroscopic sensor data;

wherein the comparing is comparing each of the plurality of gain-adjusted integrated gyroscopic sensor data with observed magnetic sensor data to create a plurality of error measures;

wherein the determining the updated gyroscopic sensor gain parameter is determining an expected gyroscopic sensor gain parameter based on the plurality of error measures; and

selecting a subsequent plurality of stored gyroscopic sensor gain parameters for use with a subsequent time-series of gyroscopic data based on the plurality of error measures.

23. The electronic device of claim 22, wherein the selecting the subsequent plurality of stored gyroscopic sensor gain parameters is performed to include a first gyroscopic sensor gain parameter that is significantly less than the expected gyroscopic sensor gain parameter and a second gyroscopic sensor gain parameter that is significantly more than the expected gyroscopic sensor gain parameter.

24. The electronic device of claim 21, wherein the period of time is a first period of time and wherein the causing is performed in real-time before a second period of time commences.

25. The electronic device of claim 21, wherein the period of time is a first period of time, wherein the error measure is a first error measure, wherein the causing is performed after a second period of time completes, wherein a second error measure is associated with the second period of time, and wherein the determining the updated gyroscopic sensor gain parameter is based on both the first error measure and the second error measure.

26. The electronic device of claim 21, wherein the circuitry is further adapted to perform the following step of modifying a rotational orientation bias of the gyro based on the integrated gyroscopic sensor data.

27. The electronic device of claim 21, wherein the period of time is a first period of time and wherein the error measure is a first error measure, the mobile electronic device further comprising:

the memory adapted for storing gyroscopic data from the first period of time and at least on previous period of time;

wherein the memory further stores instructions configured to instruct the microprocessor to;

select the at least one previous period of time; and

receive previous gyroscopic sensor data associated with the at least one previous period of time;

wherein the determination of the updated gyroscopic sensor gain parameter is based on the received previous gyroscopic sensor data.

28. A method comprising:

receiving at a processor in an electronic device a time-series of gyroscopic sensor data associated with a period of time from a gyroscopic sensor contained within the electronic device;

integrating the time-series of gyroscopic sensor data into a gyroscopic quaternion;

receiving a time-series of magnetic sensor data associated with the period of time from a magnetic sensor contained within the electronic device;

converting the time-series of magnetic sensor data into a magnetic quaternion;

comparing the gyroscopic quaternion with the magnetic quaternion to create an error measure for the period of time;

determining an updated gyroscopic sensor gain parameter based on the error measure; and

causing the stored gyroscopic sensor gain parameter to be changed to the updated gyroscopic sensor gain parameter such that subsequent gyroscopic sensor data shall be adjusted by the updated gyroscopic sensor gain parameter.

29. The method of claim 28, wherein the stored gyroscopic sensor gain parameter is a first stored gyroscopic sensor gain parameter of a plurality of stored gyroscopic sensor gain parameters, and wherein the method further includes:

integrating the time-series of gyroscopic sensor data using each of the plurality of stored gyroscopic sensor gain parameters to create a plurality of gain-adjusted gyroscopic quaternions;

wherein the comparing is comparing each of the plurality of gain-adjusted integrated gyroscopic quaternions with the magnetic quaternion to create a plurality of error quaternions;

wherein the determining the updated gyroscopic sensor gain parameter is determining an expected optimal gyroscopic sensor gain parameter based on the plurality of error quaternions; and

selecting a subsequent plurality of stored gyroscopic sensor gain parameters for use with a subsequent time-series of gyroscopic data based on the plurality of error quaternions.

30. The method of claim 29, wherein the selecting the subsequent plurality of stored gyroscopic sensor gain parameters is performed to include a first gyroscopic sensor gain parameter that is significantly less than the expected optimal gyroscopic sensor gain parameter and a second gyroscopic sensor gain parameter that is significantly more than the optimal gyroscopic sensor gain parameter.

31. The method of claim 28, wherein the period of time is a first period of time and wherein the causing is performed in real-time before a second period of time commences.

32. The method of claim 28, wherein the period of time is a first period of time, wherein the error quaternion is a first error quaternion, wherein the causing is performed after a second period of time completes, wherein a second error quaternion is associated with the second period of time, and wherein the determining the updated gyroscopic sensor gain parameter is based on both the first error quaternion and the second error quaternion.

33. The method of claim 28, further comprising:

modifying a rotational orientation bias of the gyro sensor based on the gyroscopic quaternion.

34. The method of claim 28, wherein the period of time is a first period of time and wherein the error quaternion is a first error quaternion, the method further comprising:

receiving previous gyroscopic sensor data associated with the at least one previous period of time; and

wherein the determining the updated gyroscopic sensor gain parameter is based on the received previous gyroscopic sensor data.