Frequency locking of resonators for improved temperature control of gyroscopes

• US 9,038,459 B1
• Filed: 02/27/2012
• Issued: 05/26/2015
• Est. Priority Date: 12/14/2009
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Kubena, Randall L.
• Primary Examiner(s): Patel, Harshad R
• Application Number:
  US13/405,658
• Time in Patent Office: 1,184 Days
• Field of Search: 73/17.7, 735/040.2, 735/040.4, 74/56.D
• US Class Current: 73/497
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5783 Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719

Abstract

A precision gyroscope includes a gyroscope, means for receiving an external clock reference, and circuitry coupled to the means for receiving the external clock reference and adapted for stabilizing a temperature and a frequency of the gyroscope.

Claims

1. A precision gyroscope comprising:

a gyroscope, wherein the gyroscope has a frequency;

a clock reference, wherein the clock reference has a frequency; and

circuitry coupled to the clock reference and to the gyroscope, the circuitry configured for stabilizing a temperature and the frequency of the gyroscope;

wherein the frequency of the clock reference is a simple multiple greater than 1 of the frequency of the gyroscope.

2. The precision gyroscope of claim 1:

wherein the gyroscope and the circuitry are in a first housing or on a semiconductor substrate; and

wherein the semiconductor substrate comprises silicon (Si), silicon germanium (SiGe), gallium arsenide (GaAs), or indium phosphide (InP).

3. The precision gyroscope of claim 1 wherein the gyroscope and the clock reference share a common temperature controlled housing, or wherein the gyroscope and the clock reference are in separate temperature controlled housings.

4. The precision gyroscope of claim 1 wherein the gyroscope is a vibrating mode gyroscope.

5. The precision gyroscope of claim 1 wherein the gyroscope is a disk resonator gyroscope.

6. The precision gyroscope of claim 1 wherein the circuitry further comprises a feedback loop coupled to the gyroscope and the clock reference for stabilizing the temperature and frequency of the gyroscope.

7. The precision gyroscope of claim 6 wherein the feedback loop comprises a phase-locked loop.

8. The precision gyroscope of claim 6 wherein the feedback loop is coupled to a frequency controller to electronically bias a voltage in the gyroscope.

9. The precision gyroscope of claim 6 wherein the feedback loop is coupled to a heater for controlling a temperature of the gyroscope.

10. The precision gyroscope of claim 9:

wherein the heater is mounted on a substrate on which the gyroscope is mounted;

or

wherein the heater is mounted on a cap enclosing the gyroscope on the substrate.

11. The precision gyroscope of claim 6:

wherein the gyroscope and the clock reference are in separate temperature controlled housings;

wherein the feedback loop is coupled to a first heater for controlling a temperature of the gyroscope; and

wherein the feedback loop is coupled to a second heater for controlling a temperature of the clock reference.

12. The precision gyroscope of claim 1:

wherein the clock reference comprises a quartz resonator clock; and

further comprising;

a thermistor coupled to the quartz resonator clock for stabilizing a frequency of the quartz resonator clock.

13. The precision gyroscope of claim 12 wherein the quartz resonator clock comprises an SC-cut crystal resonator.

14. The precision gyroscope of claim 1:

wherein the clock reference comprises an atomic clock.

15. The precision gyroscope of claim 1 further comprising:

an electronic circuit;

wherein the clock reference is a timing source for the electronic circuit.

16. The precision gyroscope of claim 1 further comprising:

a global positioning system; and

wherein the clock reference is a timing source for the global positioning system.

17. The precision gyroscope of claim 1:

wherein the gyroscope and the circuitry are in a first housing or on a semiconductor substrate; and

wherein the clock reference is in a second housing.

18. The precision gyroscope of claim 1 wherein the circuitry comprises:

a divider connected to the clock reference, the divider having an output that has a divided frequency of the frequency of the clock reference; and

a phase lock loop having a first input connected to the output of the divider and a second input connected to the frequency of the gyroscope, and having a phase lock loop output configured for stabilizing a temperature and the frequency of the gyroscope.

19. The precision gyroscope of claim 18:

wherein the phase lock loop output is coupled to a frequency controller for controlling the frequency of the gyroscope; and

wherein the phase lock loop output is coupled to a heater for controlling a temperature of the gyroscope.

20. A precision gyroscope comprising:

a gyroscope, wherein the gyroscope has a frequency;

an external clock reference, wherein the external clock reference has a frequency; and

circuitry coupled to the external clock reference and to the gyroscope, the circuitry configured for stabilizing a temperature and a frequency of the gyroscope;

wherein the frequency of the external clock reference is a simple multiple greater than 1 of the frequency of the gyroscope.

21. The precision gyroscope of claim 20 wherein the gyroscope is a disk resonator gyroscope.

22. The precision gyroscope of claim 20 the circuitry comprises:

a feedback loop coupled to the gyroscope and the external clock reference for stabilizing the temperature and frequency of the gyroscope; and

wherein the feedback loop comprises a phase-locked loop.

23. The precision gyroscope of claim 20 wherein the circuitry comprises:

a divider connected to the external clock reference, the divider having an output that has a divided frequency of the frequency of the external clock reference; and

a phase lock loop having a first input connected to the output of the divider and a second input connected to the frequency of the gyroscope, and having a phase lock loop output configured for stabilizing a temperature and the frequency of the gyroscope.

24. The precision gyroscope of claim 23:

wherein the phase lock loop output is coupled to a frequency controller for controlling the frequency of the gyroscope; and

wherein the phase lock loop output is coupled to a heater for controlling a temperature of the gyroscope.