Vibrating-mass gyroscope systems and method

• US 9,726,491 B2
• Filed: 07/25/2014
• Issued: 08/08/2017
• Est. Priority Date: 07/25/2014
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Inventors: Stewart, Robert E.
• Primary Examiner(s): West, Paul
• Assistant Examiner(s): Zhong, Xin
• Application Number:
  US14/341,380
• Publication Number:
  US 20160025493A1
• Time in Patent Office: 1,110 Days
• CPC Class Codes: G01C 19/5705 using masses driven in reciprocating rotary motion about an axis
• CPC Class Codes: G01C 19/5733 Structural details or topology

Abstract

One embodiment of the invention includes a vibrating-mass gyroscope system. A sensor system includes a substantially planar vibrating-mass including opposite first and second surfaces and electrodes that extend longitudinally in a periodic pattern across the first and/or second surfaces. The electrodes include sets of drive and sense electrodes that are capacitively coupled to respective matching sets of drive and sense electrodes associated with a housing and which are separated from and facing the respective first and second surfaces. A gyroscope controller generates a drive signal provided to one of the array of drive electrodes and the substantially matching array of drive electrodes to provide for in-plane periodic oscillatory motion of the vibrating-mass, and generates a force-rebalance signal that is provided to one of the array of sense electrodes and the substantially matching array of sense electrodes to calculate rotation of the vibrating-mass gyroscope system about an input axis.

Claims

1. A vibrating-mass gyroscope system comprising:

a sensor system comprising a substantially planar vibrating-mass comprising a first surface, a second surface opposite the first surface, and a plurality of electrodes that extend longitudinally in a periodic pattern across at least one of the first and second surfaces, the plurality of electrodes comprising an array of drive electrodes, an array of sense electrodes, and an array of quadrature electrodes arranged at a 45°

angle with respect to each of the sets of drive and sense electrodes, the array of drive electrodes, the array of sense electrodes, and the array of quadrature electrodes being capacitively coupled to a substantially matching array of drive electrodes, a substantially matching array of sense electrodes, and a substantially matching array of quadrature electrodes, respectively, associated with a housing and which are separated from and facing the respective at least one of the first and second surfaces, the substantially matching array of quadrature electrodes being arranged at a 45°

angle with respect to each of the substantially matching sets of drive and sense electrodes; and

a gyroscope controller configured to generate a drive signal that is provided to one of the array of drive electrodes and the substantially matching array of drive electrodes to provide for an in-plane periodic oscillatory motion of the substantially planar vibrating-mass, and to generate a force-rebalance signal that is provided to one of the array of sense electrodes and the substantially matching array of sense electrodes to calculate a rotation of the vibrating-mass gyroscope system about an input axis.

2. The system of claim 1, wherein the array of drive electrodes and the array of sense electrodes are each arranged longitudinally in the periodic pattern in respective orthogonal axes with respect to each other, and wherein the substantially matching array of drive electrodes and the substantially matching array of sense electrodes are each arranged longitudinally in the periodic pattern in respective orthogonal axes with respect to each other.

3. The system of claim 1, wherein the gyroscope controller is further configured to generate a quadrature signal that is provided to one of the array of quadrature electrodes and the substantially matching array of quadrature electrodes to substantially mitigate quadrature coupling into the force-rebalance signal.

4. The system of claim 1, wherein the substantially planar vibrating-mass comprises a first array of drive electrodes and a first array of sense electrodes on the first surface and comprises a second array of drive electrodes and a second array of sense electrodes on the second surface, and wherein the housing comprises a first substantially matching array of drive electrodes and a first substantially matching array of sense electrodes respectively separated from and facing the first surface and comprises a second substantially matching array of drive electrodes and a second substantially matching array of sense electrodes respectively separated from and facing the second surface.

5. The system of claim 1, wherein the drive signal is provided to the one of the array of drive electrodes and the substantially matching array of drive electrodes to provide for the in-plane periodic oscillatory motion of the substantially planar vibrating-mass in a direction that is orthogonal with respect to a force that is generated in response to the force-rebalance signal in response to rotation of the vibrating-mass gyroscope system about the input axis.

6. The system of claim 1, wherein the sensor system comprises a plurality of substantially planar vibrating-masses arranged in pairs, each of the plurality of substantially planar vibrating-masses comprising a first surface, a second surface opposite the first surface, and a plurality of electrodes that extend longitudinally in a periodic pattern across at least one of the first and second surfaces.

7. The system of claim 6, 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 substantially planar 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 in alternate and opposite directions for each of the plurality of substantially planar vibrating-masses with respect to a given pair.

8. The system of claim 1, wherein the gyroscope controller is configured to provide a DC quadrature signal to one of the array of quadrature electrodes and the substantially matching array of quadrature electrodes to substantially mitigate quadrature coupling into the force-rebalance signal.

9. The system of claim 1, wherein the vibrating-mass is coupled to the housing via at least one spring-mass system, wherein the gyroscope controller is configured to generate a carrier signal having a frequency that is greater than a resonant frequency of the at least one spring-mass system, wherein the drive signal and the force-rebalance signal are generated at a frequency that is approximately equal to the resonant frequency of the at least one spring-mass system based on demodulating pickoff signals associated with the plurality of electrodes at the frequency of the carrier signal.

10. 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 one of an array of drive electrodes that extend longitudinally in a periodic pattern across at least one of a first surface and a second surface of a substantially planar vibrating-mass and a substantially matching array of drive electrodes that extend longitudinally in a periodic pattern across at least one of a first surface and a second surface of a housing, wherein the first surface of the substantially planar vibrating-mass faces the first surface of the housing and the second surface of the substantially planar vibrating-mass faces the second surface of the housing;

providing a drive signal to the one of the array of drive electrodes of the substantially planar vibrating-mass and the substantially matching array of drive electrodes of the housing based on the drive pickoff signal to provide an in-plane periodic oscillatory motion of the substantially planar vibrating-mass;

monitoring a force-rebalance pickoff signal associated with one of an array of sense electrodes that extend longitudinally in a periodic pattern across at least one of the first and second surfaces of the substantially planar vibrating-mass and a substantially matching array of sense electrodes that extend longitudinally in a periodic pattern across at least one of the first and second surfaces of the housing;

providing a force-rebalance signal to the one of the array of sense electrodes of the substantially planar vibrating-mass and the substantially matching array of sense electrodes of the housing based on the force-rebalance pickoff signal to calculate a rotation of the vibrating-mass gyroscope system about an input axis;

generating a DC quadrature signal; and

providing the DC quadrature signal to one of an array of quadrature electrodes that extend in a periodic pattern across at least one of the first and second surfaces of the substantially planar vibrating-mass and a substantially matching array of sense electrodes that extend in a periodic pattern across at least one of the first and second surfaces of the housing to substantially mitigate quadrature coupling into the force-rebalance signal, the array of quadrature electrodes being arranged at a 45°

angle with respect to at least one of the sets of drive and sense electrodes.

11. The method of claim 10, wherein the array of drive electrodes and the array of sense electrodes are each arranged longitudinally in the periodic pattern in respective orthogonal axes with respect to each other across the at least one of the first and second surfaces of the respective substantially planar vibrating-mass and the housing, and wherein the substantially matching array of drive electrodes and the substantially matching array of sense electrodes are each arranged longitudinally in the periodic pattern in respective orthogonal axes with respect to each other across the at least one of the first and second surfaces of the respective substantially planar vibrating-mass and the housing.

12. The method of claim 10, wherein providing the drive signal comprises providing the drive signal to the one of the array of drive electrodes and the substantially matching array of drive electrodes to provide for the in-plane periodic oscillatory motion of the substantially planar vibrating-mass in a first direction, and wherein providing the force-rebalance signal comprises providing the force-rebalance signal to the one of the array of sense electrodes and the substantially matching array of sense electrodes to provide a force that is generated in response to the force-rebalance signal in a second direction orthogonal to the first direction based rotation of the vibrating-mass gyroscope system about the input axis.

13. The method of claim 10, wherein providing the drive signal comprises providing the drive signal to the one of the array of drive electrodes and the substantially matching array of drive electrodes associated with a plurality of substantially planar vibrating-masses arranged in pairs to provide for the in-plane periodic oscillatory motion of each of the plurality of substantially planar vibrating-masses that is out-of-phase by 180°

with respect to a given pair, and wherein providing the force-rebalance signal comprises providing the force-rebalance signal to the one of the array of sense electrodes and the substantially matching array of sense electrodes associated with the plurality of substantially planar vibrating-masses to provide a force in alternate and opposite directions with respect to a given pair.

14. A vibrating-mass gyroscope system comprising:

a sensor system comprising a plurality of substantially planar vibrating-masses that each comprise a first surface, a second surface opposite the first surface, and a plurality of electrodes that extend longitudinally in a periodic pattern across each of the first and second surfaces, the plurality of electrodes comprising an array of drive electrodes, an array of sense electrodes, and an array of quadrature electrodes arranged at a 45°

angle with respect to each of the sets of drive and sense electrodes, the array of drive electrodes, the array of sense electrodes, and the array of quadrature electrodes being capacitively coupled to a substantially matching array of drive electrodes, a substantially matching array of sense electrodes, and a substantially matching array of quadrature electrodes, respectively, associated with a housing and which are separated from and facing the respective at least one of the first and second surfaces of each of the plurality of vibrating-masses, the substantially matching array of quadrature electrodes being arranged at a 45°

angle with respect to each of the substantially matching sets of drive and sense electrodes; and

a gyroscope controller configured to generate a drive signal that is provided to one of the array of drive electrodes and the substantially matching array of drive electrodes associated with each of the plurality of vibrating-masses to provide for an in-plane periodic oscillatory motion of each of the plurality of substantially planar vibrating-masses, and to generate a force-rebalance signal that is provided to one of the array of sense electrodes and the substantially matching array of sense electrodes associated with each of the plurality of vibrating-masses to calculate a rotation of the vibrating-mass gyroscope system about an input axis, and to generate a quadrature signal that is provided to one of the array of quadrature electrodes and the substantially matching array of quadrature electrodes associated with each of the plurality of substantially planar vibrating-masses to substantially mitigate quadrature coupling into the force-rebalance signal.

15. The system of claim 14, wherein the array of drive electrodes and the array of sense electrodes associated with each of the plurality of vibrating-masses are each arranged longitudinally in the periodic pattern in respective orthogonal axes with respect to each other on each of the first and second surfaces of each of the respective plurality of vibrating-masses, and wherein the substantially matching array of drive electrodes and the substantially matching array of sense electrodes on the housing and respectively associated with each of the first and second surfaces of each of the plurality of substantially planar vibrating-masses are each arranged longitudinally in the periodic pattern in respective orthogonal axes with respect to each other.

16. The system of claim 14, wherein the plurality of substantially planar vibrating-masses are arranged in pairs, 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 substantially planar 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 in alternate and opposite directions for each of the plurality of substantially planar vibrating-masses with respect to a given pair.