VIBRATING-MASS GYROSCOPE SYSTEMS AND METHOD

• US 20160231118A1
• Filed: 02/10/2015
• Published: 08/11/2016
• Est. Priority Date: 02/10/2015
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Inventors: TRUSOV, ALEXANDER, ROZELLE, DAVID M.
• Granted Patent: US 9,810,535 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5726 Signal processing
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• 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

One embodiment of the invention includes a vibrating-mass gyroscope system. The system includes a sensor system comprising a vibrating-mass and a plurality of electrodes coupled to the vibrating-mass that are configured to facilitate in-plane motion of the vibrating-mass. The system also includes a gyroscope controller configured to generate a drive signal that is provided to a first set of the plurality of electrodes to provide an in-plane periodic oscillatory motion of the vibrating-mass along a drive axis, to generate a force-rebalance signal that is provided to a second set of the plurality of electrodes to calculate a rotation of the vibrating-mass gyroscope system about an input axis, and to generate a quadrature signal that is provided to a third set of the plurality of electrodes to substantially mitigate quadrature effects associated with the vibrating-mass.

Claims

1. A vibrating-mass gyroscope system comprising:

a sensor system comprising a vibrating-mass and a plurality of electrodes coupled to the vibrating-mass that are configured to facilitate in-plane motion of the vibrating-mass; and

a gyroscope controller configured to generate a drive signal that is provided to a first set of the plurality of electrodes to provide an in-plane periodic oscillatory motion of the vibrating-mass along a drive axis, to generate a force-rebalance signal that is provided to a second set of the plurality of electrodes to calculate a rotation of the vibrating-mass gyroscope system about an input axis, and to generate a quadrature signal that is provided to a third set of the plurality of electrodes to substantially mitigate quadrature effects associated with the vibrating-mass.

2. The system of claim 1, wherein the in-plane periodic oscillatory motion of the vibrating-mass is provided in response to a drive axis force along the drive axis generated in response to the drive signal, wherein the force-rebalance signal is configured to generate a force-rebalance force along a second axis that is orthogonal to the drive axis, and wherein the quadrature signal is provided to generate a quadrature force along a third axis that is arranged at approximately 45°

relative to the first and second axes.

3. The system of claim 1, wherein the vibrating-mass is configured in a substantially planar octagonal shape, wherein the plurality of electrodes comprises eight electrode shuttles that are each arranged, respectively, at a respective one of the sides of the periphery of the substantially planar octagonal shape to pull the vibrating-mass along a respective single-axis in respective directions orthogonal with the eight sides of the periphery of the substantially planar octagonal shape.

4. The system of claim 1, wherein the quadrature signal comprises a first quadrature signal and a second quadrature signal, wherein the third set of the plurality of electrodes comprises:

a first pair of quadrature electrode arrangements that are arranged opposite each other with respect to the vibrating-mass and which are each configured to receive the first quadrature signal; and

a second pair of quadrature electrode arrangements that are arranged opposite each other with respect to the vibrating-mass and orthogonally with respect to the first pair of quadrature electrode arrangements and which are each configured to receive the second quadrature signal.

5. The system of claim 1, wherein the gyroscope controller is further configured to calculate a magnitude of the quadrature effects based on a frequency of the in-plane motion of the vibrating-mass, and is further configured to set an amplitude of the quadrature signal to substantially mitigate the quadrature effects in a feedback manner based on the magnitude of the quadrature effects.

6. The system of claim 1, wherein the quadrature signal is a DC signal having a predetermined amplitude that corresponds to an electrostatic force sufficient to substantially mitigate the quadrature effects associated with the vibrating-mass.

7. The system of claim 1, wherein the sensor system comprises:

a plurality of vibrating-masses arranged in pairs and configured in a substantially planar arrangement with respect to each other; and

a plurality of electrodes coupled to each of the plurality of vibrating-masses that are configured to facilitate in-plane motion of each of the plurality of vibrating-masses.

8. The system of claim 7, wherein the gyroscope controller is configured to generate the drive signal to provide for the in-plane periodic oscillatory motion of each of the plurality of vibrating-masses in a manner that is out-of-phase by 180°

with respect to a given pair, and wherein the gyroscope controller is configured to generate the force-rebalance signal to generate a force-rebalance force in alternate and opposite directions for each of the plurality of vibrating-masses with respect to a given pair.

9. The system of claim 7, wherein the plurality of electrodes comprises a plurality of electrode shuttles, wherein at least one of the plurality of electrode shuttles of each of the plurality of vibrating-masses is coupled to at least one of the plurality of electrode shuttles of at least one of the remaining plurality of vibrating-masses via a spring flexure.

10. The system of claim 7, wherein the gyroscope controller is configured to provide drive signals to each of the plurality of vibrating masses along a respective drive axis to provide the in-plane periodic oscillatory motion of the respective plurality of vibrating-masses, to provide force-rebalance signals to provide a force-rebalance force along a respective sense-axis of the respective plurality of vibrating-masses, and to provide quadrature signals to each of the plurality of vibrating masses to provide quadrature forces along respective quadrature axes of the respective plurality of vibrating-masses, wherein the gyroscope controller is further configured to implement a self-calibration procedure of the sensor system based on periodically switching at least two of the drive axis, the sense axis, and the quadrature axes of each of the plurality of vibrating-masses in each of separate time durations.

11. A method for calculating rotation about an input axis in a vibrating-mass gyroscope system, the method comprising:

monitoring a drive pickoff signal associated with a set of drive electrode shuttles that is coupled to a vibrating-mass;

providing a drive signal to the set of drive electrode shuttles to provide an in-plane periodic oscillatory motion of the vibrating-mass;

monitoring a force-rebalance pickoff signal associated with a set of sense electrode shuttles that is coupled to the vibrating-mass;

providing a force-rebalance signal to the set of sense electrode shuttles based on the force-rebalance pickoff signal to calculate a rotation of the vibrating-mass gyroscope system about the input axis; and

providing a quadrature signal to a set of quadrature electrode shuttles that is coupled to the vibrating-mass to substantially mitigate quadrature effects.

12. The method of claim 11, wherein the vibrating-mass is configured in an octagonal shape, wherein the set of drive electrode shuttles comprises a pair of drive electrode shuttles arranged opposite each other with respect to the vibrating-mass along a drive axis to provide for single-axis periodic motion along the drive axis, wherein the set of sense electrode shuttles comprises a pair of sense electrode shuttles arranged opposite each other with respect to the vibrating-mass along a sense axis that is orthogonal with respect to the drive axis to provide for single-axis force-rebalance along the sense axis, and wherein the set of quadrature electrode shuttles comprises a pair of quadrature electrode shuttles arranged opposite each other with respect to the vibrating-mass and arranged along a first quadrature axis that is approximately 45°

with respect to the drive axis and the sense axis to provide for single-axis quadrature force along the first quadrature axis.

13. The method of claim 12, wherein the quadrature signal is a first quadrature signal, and wherein the pair of quadrature electrode shuttles is a first pair of quadrature electrode shuttles arranged along a first quadrature axis, wherein providing the quadrature signal comprises:

providing the first quadrature signal to the first pair of quadrature electrode shuttles; and

providing a second quadrature signal to a second pair of quadrature electrode shuttles arranged opposite each other with respect to the vibrating-mass and arranged along a second quadrature axis that is orthogonal with respect to the first quadrature axis.

14. The method of claim 11, further comprising:

calculating a magnitude of the quadrature effects based on a frequency of the in-plane motion of the vibrating-mass; and

setting an amplitude of the quadrature signal to substantially mitigate the quadrature effects in a feedback manner based on the magnitude of the quadrature effects.

15. The method of claim 11, wherein the vibrating-mass is a first vibrating-mass, the vibrating-mass gyroscope system comprising a second vibrating-mass, the method further comprising:

monitoring a second drive pickoff signal associated with a second set of drive electrode shuttles that is coupled to the second vibrating-mass;

providing a second drive signal to the second set of drive electrode shuttles to provide an in-plane periodic oscillatory motion of the second vibrating-mass;

monitoring a second force-rebalance pickoff signal associated with a second set of sense electrode shuttles that is coupled to the second vibrating-mass;

providing a second force-rebalance signal to the second set of sense electrode shuttles based on the second force-rebalance pickoff signal;

providing a second quadrature signal to a second set of quadrature electrode shuttles that is coupled to the second set of quadrature electrode shuttles based on the force-rebalance pickoff signal to substantially mitigate quadrature effects; and

calculating the rotation of the vibrating-mass gyroscope system about the input axis based on at least one of the first and second force-rebalance pickoff signals.

16. The method of claim 15, wherein providing the drive signal comprises providing the drive signal to the set of drive electrode shuttles associated with the first vibrating-mass along a drive axis in a first direction, and wherein providing the second drive signal comprises providing the second drive signal to the second set of drive electrode shuttles associated with the second vibrating-mass along the drive axis in a second direction opposite the first direction, such that the in-plane periodic motion of the first and second vibrating-masses is out-of-phase by 180°

.

17. A vibrating-mass gyroscope system comprising:

a sensor system comprising a plurality of vibrating-masses and a respective plurality of sets of electrodes respectively coupled to each of the plurality of vibrating-masses, each of the plurality of sets of substantially planar vibrating masses being configured to facilitate in-plane motion of a respective one of the plurality of vibrating-masses; and

a gyroscope controller configured to generate drive signals that are provided to drive electrodes of each of the plurality of sets of electrodes to provide an in-plane periodic oscillatory motion of the respective plurality of vibrating-masses along a drive axis, to generate a force-rebalance signals that are provided to sense electrodes of each of the plurality of sets of electrodes to calculate a rotation of the vibrating-mass gyroscope system about an input axis, and to generate quadrature signals that are provided to quadrature electrodes of each of the plurality of sets of electrodes to substantially mitigate quadrature effects associated with the respective plurality of vibrating-masses.

18. The system of claim 17, wherein the in-plane periodic oscillatory motion of each of the plurality of vibrating-masses is provided in response to a drive axis force along the drive axis of each of the plurality of vibrating-masses generated in response to the drive signals, wherein the force-rebalance signals are configured to generate a force-rebalance force along a second axis of each of the plurality of vibrating-masses that is orthogonal to the respective drive axis, and wherein the quadrature signals are provided to generate a quadrature force along a third axis of each of the plurality of vibrating-masses that is arranged at approximately 45°

relative to the respective first and second axes.

19. The system of claim 17, wherein each of the plurality of vibrating-masses are configured in a substantially planar octagonal shape, wherein each of the plurality of sets of electrodes comprises eight electrode shuttles that are each arranged, respectively, at a respective one of the sides of the periphery of the substantially planar octagonal shape of each of the plurality of vibrating-masses to pull the respective one of the plurality of vibrating-masses along a respective single-axis in respective directions orthogonal with the eight sides of the periphery of the substantially planar octagonal shape.

20. The system of claim 17, wherein the gyroscope controller is configured to generate the drive signals to provide for the in-plane periodic oscillatory motion of each of the plurality of substantially planar vibrating-masses in a manner that is out-of-phase by 180°

with respect to a given pair of the plurality of vibrating-masses, and wherein the gyroscope controller is configured to generate the force-rebalance signal to generate a force-rebalance force in alternate and opposite directions for each of the plurality of substantially planar vibrating-masses with respect to a given pair.