Control component for planar resonator

• US 20100071465A1
• Filed: 09/22/2008
• Published: 03/25/2010
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: Northrop Grumman Guidance And Electronics Company, Inc.
• Original Assignee: Northrop Grumman Guidance And Electronics Company, Inc.
• Inventors: Stewart, Robert E.
• Granted Patent: US 8,011,246 B2
• Time in Patent Office: Days
• US Class Current: 73/504.20
• CPC Class Codes: G01C 19/5684 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis

Abstract

A control component of an apparatus in one example is configured to signal a plurality of electrodes arranged in at least first, second, third, and fourth radial electrode groups along first, second, third, and fourth axes at approximately 0, 45, 90, and 135 degrees, respectively, around the planar resonator. During a first time period, the control component is configured to signal: the first radial electrode group to induce a drive oscillation in the planar resonator, the third radial electrode group to sense the drive oscillation, the second radial electrode group to sense a Coriolis force induced oscillation, and the fourth radial electrode group to null the Coriolis force induced oscillation. During a second time period after the first time period, the control component is configured to signal: the second radial electrode group to induce the drive oscillation in the planar resonator, the fourth radial electrode group to sense the drive oscillation, the first radial electrode group to sense the Coriolis force induced oscillation, and the third radial electrode group to null the Coriolis force induced oscillation.

Claims

1. An apparatus, comprising:

a control component configured to signal a plurality of electrodes arranged in at least first, second, third, and fourth radial electrode groups along first, second, third, and fourth axes at approximately 0, 45, 90, and 135 degrees, respectively, around the planar resonator;

wherein, during a first time period, the control component is configured to signal;

the first radial electrode group to induce a drive oscillation in the planar resonator,

the third radial electrode group to sense the drive oscillation,

the second radial electrode group to sense a Coriolis force induced oscillation, and

the fourth radial electrode group to null the Coriolis force induced oscillation;

wherein, during a second time period after the first time period, the control component is configured to signal;

the second radial electrode group to induce the drive oscillation in the planar resonator,

the fourth radial electrode group to sense the drive oscillation,

the first radial electrode group to sense the Coriolis force induced oscillation, and

the third radial electrode group to null the Coriolis force induced oscillation.

2. The apparatus of claim 1, wherein the plurality of electrodes within the first, second, third, and fourth radial electrode groups are arranged in alternating concentric rings about a center support of the planar resonator;

wherein the first, second, third, and fourth axes extend across a diameter of the planar resonator and approximately through the center support of the planar resonator.

3. The apparatus of claim 2, wherein the first, second, third, and fourth radial electrode groups comprise electrodes on opposite sides of the center support of the planar resonator along the first, second, third, and fourth axes, respectively.

4. The apparatus of claim 1, wherein, during a third time period after the second time period, the control component is configured to signal:

the first radial electrode group to induce a drive oscillation in the planar resonator,

the third radial electrode group to sense the drive oscillation,

the second radial electrode group to sense a Coriolis force induced oscillation, and

the fourth radial electrode group to null the Coriolis force induced oscillation.

5. The apparatus of claim 1, wherein the control component determines an angular rate of the planar resonator based on the Coriolis force induced oscillation.

6. The apparatus of claim 5, wherein the plurality of electrodes and the planar resonator comprise a portion of a first gyroscope;

wherein the first time period corresponds to a normal polarity of the first gyroscope and the second time period corresponds to a reverse polarity of the first gyroscope;

wherein the control component is configured to signal a plurality of electrodes of a second gyroscope, wherein the first and second gyroscopes comprise a same sensitive axis;

wherein the control component is configured to perform a plurality of change-overs to transition the first gyroscope and the second gyroscope between the normal and reverse polarities.

7. The apparatus of claim 6, wherein the angular rate comprises an angular rate of the first gyroscope and the second gyroscope;

wherein the control component is configured to determine the angular rate through employment of a Kalman filter that receives outputs from the first and second gyroscopes.

8. The apparatus of claim 7, wherein the control component is configured to perform the plurality of change-overs such that the respective polarities of the first and second gyroscopes are:

normal and normal during the first period,

reverse and normal during the second period,

reverse and reverse during a third period, and

normal and reverse during a fourth period;

wherein the control component is configured to employ measurements of the outputs from the first and second gyroscopes taken from the first, second, third, and fourth periods to determine the angular rate of the planar resonator with compensation for the bias signals.

9. The apparatus of claim 8, wherein the control component is configured to measure the outputs of from the first and second gyroscopes during the first, second, third, and fourth periods after a pre-determined setup time.

10. The apparatus of claim 9, wherein a duration of the first, second, third, and fourth periods is based on a native integration time of the first and second gyroscopes.

11. The apparatus of claim 10, wherein the control component is communicatively coupled with a plurality of gyroscopes, wherein the plurality of gyroscopes comprise the first and second gyroscopes, wherein the plurality of gyroscopes comprise a same sensitive axis;

wherein the control component is configured to perform a plurality of change-overs of the plurality of gyroscopes with a round-robin procedure.

12. A method, comprising the steps of:

signaling, during a first time period, a first radial electrode group to induce a drive oscillation in a planar resonator;

signaling, during the first time period, a third radial electrode group to sense the drive oscillation;

signaling, during the first time period, a second radial electrode group to sense a Coriolis force induced oscillation;

signaling, during the first time period, a fourth radial electrode group to null the Coriolis force induced oscillation;

signaling, during a second time period after the first time period, the second radial electrode group to induce the drive oscillation in the planar resonator;

signaling, during the second time period, the fourth radial electrode group to sense the drive oscillation;

signaling, during the second time period, the first radial electrode group to sense the Coriolis force induced oscillation; and

signaling, during the second time period, the third radial electrode group to null the Coriolis force induced oscillation;

wherein the first, second, third, and fourth radial electrode groups are arranged along first, second, third, and fourth axes at approximately 0, 45, 90, and 135 degrees, respectively, around the planar resonator.

13. The method of claim 12, further comprising the steps of:

signaling, during a third time period after the second time period, the first radial electrode group to induce the drive oscillation in the planar resonator;

signaling, during the third time period, the third radial electrode group to sense the drive oscillation;

signaling, during the third time period, the second radial electrode group to sense the Coriolis force induced oscillation;

signaling, during the third time period, the fourth radial electrode group to null the Coriolis force induced oscillation.

14. The method of claim 12, further comprising the step of:

determining an angular rate of the planar resonator based on the Coriolis force induced oscillation.

15. The method of claim 12, wherein a first gyroscope comprises the planar resonator, the method further comprising the steps of:

performing a first change-over to transition the first gyroscope from the first time period to the second time period;

processing measurements from the first gyroscope and a second gyroscope during the first time period and measurements from the first gyroscope and the second gyroscope during the second time period to perform self-calibration of the first and second gyroscopes.

16. The method of claim 15, wherein the step of performing the second change-over comprises the step of:

performing the second change-over after a pre-determined time period from the first change-over.

17. The method of claim 16, further comprising the step of:

performing a plurality of change-overs to transition a plurality of gyroscopes with a round-robin procedure, wherein the plurality of gyroscopes comprises the first and second gyroscopes, wherein the plurality of change-overs are separated by the predetermined time period.

18. A method, comprising the steps of:

signaling a plurality of electrodes of a gyroscope during a first time period to;

induce and sense drive oscillations along a first set of orthogonal axes of a planar resonator of the gyroscope, and to

sense and null a Coriolis force induced oscillation along a second set of orthogonal axes of the planar resonator,

wherein the first set of orthogonal axes are offset 45 degrees from the second set of orthogonal axes;

signaling the plurality of electrodes of the gyroscope during a second time period to;

induce and sense drive oscillations along the second set of orthogonal axes, and to sense and null the Coriolis force induced oscillation along the second set of orthogonal axes.

19. The method of claim 18, wherein a first gyroscope comprises the planar resonator, the method further comprising the steps of:

performing a first change-over to transition the first gyroscope from the first time period to the second time period;

processing measurements from the first gyroscope and a second gyroscope during the first time period and measurements from the first gyroscope and the second gyroscope during the second time period to perform self-calibration of the first and second gyroscopes.

20. The method of claim 19, further comprising the step of:

performing a plurality of change-overs to transition a plurality of gyroscopes with a round-robin procedure, wherein the plurality of gyroscopes comprises the first and second gyroscopes, wherein the plurality of change-overs are separated by a predetermined time period.