ANGLE-MEASURING METHOD AND ANGLE-MEASURING GYROSCOPE SYSTEM FOR IMPLEMENTING THE SAME

• US 20110005315A1
• Filed: 11/03/2009
• Published: 01/13/2011
• Est. Priority Date: 07/09/2009
• Status: Active Grant

• Current Assignee: National Chiao Tung University (Government of The Republic of China)
• Original Assignee: National Chiao Tung University (Government of The Republic of China)
• Inventors: CHI, Chien-Yu, CHEN, Tsung-Lin
• Granted Patent: US 8,166,817 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5726 Signal processing

Abstract

An angle-measuring method includes: configuring a state observer to calculate a set of estimated signals based on a set of previously calculated estimated parameters; configuring the state observer to calculate a gain thereof using a dynamic equation associated with a gyroscope; configuring the state observer to calculate a set of currently calculated estimated parameters using the dynamic equation associated with the gyroscope based on the gain calculated by the state observer, a set of sensing signals generated by a sensing module, and the estimated signals calculated by the state observer; and configuring an angle calculator to calculate an angle of rotation of the gyroscope based on a position and a velocity in the currently calculated estimated parameters calculated by the state observer and a stiffness coefficient of the gyroscope. An angle-measuring gyroscope system that implements the angle-measuring method is also disclosed.

Claims

1. An angle-measuring method for calculating an angle of rotation of a gyroscope of an angle-measuring gyroscope system, the gyroscope including a proof mass that oscillates in an x-y plane defined by mutually orthogonal x and y axes, the angle-measuring gyroscope system including a sensing module, a state observer, and an angle calculator, the sensing module being configured to detect motion of the proof mass, and to generate a set of sensing signals that correspond to the motion of the proof mass detected thereby and that indicate x and y components of a position of the proof mass, said angle-measuring method comprising:

A) configuring the state observer to calculate a set of estimated signals based on a set of previously calculated estimated parameters, the previously calculated estimated parameters corresponding to a set of system parameters of the angle-measuring gyroscope system, the system parameters of the angle-measuring gyroscope system including x and y components of a position of the proof mass, x and y components of a velocity of the proof mass, x and y components of an error of the sensing module, and an angular rate of the gyroscope about a z-axis orthogonal to the x and y axes;

B) configuring the state observer to calculate a gain thereof using a dynamic equation associated with the gyroscope;

C) configuring the state observer to calculate a set of currently calculated estimated parameters using the dynamic equation associated with the gyroscope based on the gain calculated in step B), the sensing signals generated by the sensing module, and the estimated signals calculated in step A); and

D) configuring the angle calculator to calculate an angle of rotation of the gyroscope about the z-axis based on a position and a velocity in the currently calculated estimated parameters calculated in step C) and a stiffness coefficient of the gyroscope.

2. The angle-measuring method as claimed in claim 1, wherein the currently calculated estimated parameters calculated in step C) correspond to the previously calculated estimated parameters from which the estimated signals are calculated in step A).

3. The angle-measuring method as claimed in claim 1, wherein, in step D), the angle of rotation (φ

) of the gyroscope is calculated according to

4. The angle-measuring method as claimed in claim 1, wherein, in step C), the currently calculated estimated parameters ({circumflex over (X)}_m+1) are calculated according to

{circumflex over (X)}_m+1=f_d({circumflex over (X)}_m)+L_m(Z_m−

{circumflex over (Z)}_m)

where {circumflex over (X)}=f_d({circumflex over (X)}) is the dynamic equation associated with the gyroscope, {circumflex over (X)}_m are the previously calculated estimated parameters, L is the gain calculated in step B), Z are the sensing signals generated by the sensing module, {circumflex over (Z)} are the estimated signals calculated in step A), and m is the mth iteration.

5. The angle-measuring method as claimed in claim 1, wherein, in step B), the gain of the state observer is calculated further using an extended Kalman filter (EKF).

6. The angle-measuring method as claimed in claim 5, wherein, in step B), the gain of the state observer is calculated further using a fading memory technique.

7. An angle-measuring gyroscope system, comprising:

a gyroscope including a proof mass that oscillates in an x-y plane defined by mutually orthogonal x and y axes;

a sensing module coupled to said gyroscope, and configured to detect motion of said proof mass, and to generate a set of sensing signals that correspond to the motion of said proof mass detected thereby and that indicate x and y components of a position of said proof mass; and

a calculating module including

a state observer coupled to said sensing module, and configured to calculate a set of estimated signals based on a set of previously calculated estimated parameters, the previously calculated estimated parameters corresponding to a set of system parameters of said angle-measuring gyroscope system, the system parameters of said angle-measuring gyroscope system including x and y components of a position of said proof mass, x and y components of a velocity of said proof mass, x and y components of an error of said sensing module, and an angular rate of said gyroscope about a z-axis orthogonal to the x and y axes, said state observer being further configured to calculate a gain thereof using a dynamic equation associated with said gyroscope, and to calculate a set of currently calculated estimated parameters using the dynamic equation associated with said gyroscope based on the gain calculated thereby, the sensing signals generated by said sensing module, and the estimated signals calculated thereby, and

an angle calculator coupled to said state observer, and configured to calculate an angle of rotation of said gyroscope about the z-axis based on a position and a velocity in the currently calculated estimated parameters calculated by said state observer and a stiffness coefficient of said gyroscope.

8. The angle-measuring gyroscope system as claimed in claim 7, wherein the currently calculated estimated parameters calculated by said state observer correspond to the previously calculated estimated parameters from which said state observer calculates the estimated signals.

9. The angle-measuring gyroscope system as claimed in claim 7, wherein the gain of said state observer is calculated by said state observer through further use of an extended Kalman filter (EKF).

10. The angle-measuring gyroscope system as claimed in claim 9, wherein the gain of said state observer is calculated by said state observer through further use of a fading memory technique.

11. An angle-measuring method for calculating an angle of rotation of a gyroscope of an angle-measuring gyroscope system, the gyroscope including a proof mass that oscillates in an x-y plane defined by mutually orthogonal x and y axes, the angle-measuring gyroscope system including a sensing module, a driving module, a state observer, a control signal calculator, and an angle calculator, the sensing module being configured to detect motion of the proof mass, and to generate a set of sensing signals that correspond to the motion of the proof mass detected thereby and that indicate x and y components of a position of the proof mass, the driving module being configured to generate a set of control forces based on a set of control signals for controlling oscillation of the proof mass, said angle-measuring method comprising:

A) configuring the state observer to calculate a set of estimated signals based on a set of previously calculated estimated parameters, the previously calculated estimated parameters corresponding to a set of system parameters of the angle-measuring gyroscope system, the system parameters of the angle-measuring gyroscope system including x and y components of a position of the proof mass, x and y components of a velocity of the proof mass, an angular rate of the gyroscope about a z-axis orthogonal to the x and y axes, x and y components of a stiffness coefficient of the gyroscope, a stiffness coefficient of a coupling effect of the gyroscope, x and y components of a damping coefficient of the gyroscope, and a damping coefficient of a coupling effect of the gyroscope;

B) configuring the state observer to calculate a gain thereof using a dynamic equation associated with the gyroscope;

C) configuring the control signal calculator to calculate the control signals based on a stiffness coefficient, a damping coefficient, a position, and a velocity in the previously calculated estimated parameters, and a predetermined target stiffness coefficient;

D) configuring the state observer to calculate a set of currently calculated estimated parameters using the dynamic equation associated with the gyroscope based on the gain calculated in step B), the sensing signals generated by the sensing module, and the estimated signals calculated in step A); and

E) configuring the angle calculator to calculate an angle of rotation of the gyroscope about the z-axis based on a position and a velocity in the currently calculated estimated parameters calculated in step D) and the predetermined target stiffness coefficient.

12. The angle-measuring method as claimed in claim 11, wherein the currently calculated estimated parameters calculated in step D) correspond to the previously calculated estimated parameters from which the estimated signals are calculated in step A).

13. The angle-measuring method as claimed in claim 11, wherein the system parameters of the angle-measuring gyroscope system further include x and y components of an error of the sensing module.

14. The angle-measuring method as claimed in claim 11, wherein the x and y components of the stiffness coefficient of the gyroscope, the stiffness coefficient of the coupling effect of the gyroscope, the x and y components of the damping coefficient of the gyroscope, and the damping coefficient of the coupling effect of the gyroscope are normalized parameters and are normalized using a mass of the proof mass.

15. The angle-measuring method as claimed in claim 11, wherein the x and y components of the stiffness coefficient of the gyroscope, the stiffness coefficient of the coupling effect of the gyroscope, the x and y components of the damping coefficient of the gyroscope, and the damping coefficient of the coupling effect of the gyroscope are non-normalized parameters.

16. The angle-measuring method as claimed in claim 11, wherein, in step E), the angle of rotation (φ

) of the gyroscope is calculated according to

17. The angle-measuring method as claimed in claim 11, wherein, in step D), the currently calculated estimated parameters ({circumflex over (X)}_m+1) are calculated according to

{circumflex over (X)}_m+1=f_d({circumflex over (X)}_m)+BU_m+L_m(Z_m−

{circumflex over (Z)}_m)

where {circumflex over (X)}=f_d({circumflex over (X)})+BU is the dynamic equation associated with the gyroscope, {circumflex over (X)}_m are the previously calculated estimated parameters, U are the control signals calculated in step C), L is the gain calculated in step B), Z are the sensing signals generated by the sensing module, {circumflex over (Z)} are the estimated signals calculated in step A), and m is the mth iteration.

18. The angle-measuring method as claimed in claim 11, wherein, in step B), the gain of the state observer is calculated further using an extended Kalman filter (EKF).

19. The angle-measuring method as claimed in claim 18, wherein, in step B), the gain of the state observer is calculated further using a fading memory technique.

20. An angle-measuring gyroscope system, comprising:

a gyroscope including a proof mass that oscillates in an x-y plane defined by mutually orthogonal x and y axes;

a sensing module coupled to said gyroscope, and configured to detect motion of said proof mass, and to generate a set of sensing signals that correspond to the motion of said proof mass detected thereby and that indicate x and y components of a position of said proof mass;

a calculating module including

a state observer coupled to said sensing module, and configured to calculate a set of estimated signals based on a set of previously calculated estimated parameters, the previously calculated estimated parameters corresponding to a set of system parameters of said angle-measuring gyroscope system, the system parameters of said angle-measuring gyroscope system including x and y components of a position of said proof mass, x and y components of a velocity of said proof mass, an angular rate of said gyroscope about a z-axis orthogonal to the x and y axes, x and y components of a stiffness coefficient of said gyroscope, a stiffness coefficient of a coupling effect of said gyroscope, x and y components of a damping coefficient of said gyroscope, and a damping coefficient of a coupling effect of said gyroscope, said state observer being further configured to calculate a gain thereof using a dynamic equation associated with said gyroscope, and to calculate a set of currently calculated estimated parameters using the dynamic equation associated with said gyroscope based on the gain calculated thereby, the sensing signals generated by said sensing module, and the estimated signals calculated thereby,

a control signal calculator coupled to said state observer, and configured to calculate a set of control signals based on a stiffness coefficient, a damping coefficient, a position, and a velocity in the previously calculated estimated parameters, and a predetermined target stiffness coefficient, and

an angle calculator coupled to said state observer, and configured to calculate an angle of rotation of said gyroscope about the z-axis based on a position and a velocity in the currently calculated estimated parameters calculated by said state observer and a stiffness coefficient of said gyroscope; and

a driving module coupled to said control signal calculator of said calculating module and said gyroscope, and configured to generate a set of control forces based on the control signals calculated by said control signal calculator for controlling oscillation of said proof mass of said gyroscope.

21. The angle-measuring gyroscope system as claimed in claim 20, wherein the currently calculated estimated parameters calculated by said state observer correspond to the previously calculated estimated parameters from which said state observer calculates the estimated signals.

22. The angle-measuring gyroscope system as claimed in claim 20, wherein the system parameters of said angle-measuring gyroscope system further include x and y components of an error of said sensing module.

23. The angle-measuring gyroscope system as claimed in claim 20, wherein the x and y components of the stiffness coefficient of said gyroscope, the stiffness coefficient of the coupling effect of said gyroscope, the x and y components of the damping coefficient of said gyroscope, and the damping coefficient of the coupling effect of said gyroscope are normalized parameters and are normalized using amass of said proof mass.

24. The angle-measuring gyroscope system as claimed in claim 20, wherein the x and y components of the stiffness coefficient of said gyroscope, the stiffness coefficient of the coupling effect of said gyroscope, the x and y components of the damping coefficient of said gyroscope, and the damping coefficient of the coupling effect of said gyroscope are non-normalized parameters.

25. The angle-measuring gyroscope system as claimed in claim 20, wherein the gain of said state observer is calculated by said state observer through further use of an extended Kalman filter (EKF).

26. The angle-measuring gyroscope system as claimed in claim 25, wherein the gain of said state observer is calculated by said state observer calculates through further use of a fading memory technique.