Noise source for starting MEMS gyroscope

• US 6,792,802 B2
• Filed: 03/07/2002
• Issued: 09/21/2004
• Est. Priority Date: 03/07/2002
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Platt, William P.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): HANLEY, JOHN C
• Application Number:
  US10/092,819
• Publication Number:
  US 20030167842A1
• Time in Patent Office: 929 Days
• Field of Search: 735/040.4, 735/041.2, 735/043.2, 735/041.6
• US Class Current: 73/504.12
• 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: H03B 29/00 Generation of noise currents and voltages gasfilled discharge tubes with solid cathode specially adapted as noise generators H01J17/005

Abstract

By injecting noise into drive electronics, the start time of the MEMS gyroscope may be improved. A noise source is used to provide bandwidth limited white noise with a bandwidth centered substantially at the tuning fork frequency of at least one proof mass.

Claims

1. A method for improving a start time of a MEMS gyroscope system, comprising injecting bandwidth limited white noise into drive electronics connected to a MEMS gyroscope until the drive electronics locks onto a tuning fork frequency of at least one proof mass in the MEMS gyroscope.

2. The method of claim 1, wherein the MEMS gyroscope is a vibratory gyroscope.

3. The method of claim 1, wherein the MEMS gyroscope uses a Coriolis acceleration to detect rotation.

4. The method of claim 1, wherein the noise is injected into the drive electronics after applying a system power source to the MEMS gyroscope.

5. The method of claim 1, wherein the noise is injected into the drive electronics substantially before the MEMS gyroscope reaches full power.

6. The method of claim 1, wherein a bandwidth of the noise is substantially centered at the tuning fork frequency of the at least one proof mass.

7. The method of claim 1, wherein a bandwidth of the noise is substantially +/−

1000 Hertz wide.

8. The method of claim 1, wherein the drive electronics applies a drive voltage to at least one motor drive comb which causes the at least one proof mass to oscillate.

9. A system for improving a start time of a MEMS gyroscope, comprising in combination:

a MEMS gyroscope;

drive electronics connected to the MEMS gyroscope; and

a noise source that injects bandwidth limited white noise into the drive electronics until the drive electronics locks onto a tuning fork frequency of at least one proof mass in the MEMS gyroscope.

10. The system of claim 9, wherein the MEMS gyroscope is a vibratory gyroscope.

11. The system of claim 9, wherein the MEMS gyroscope uses a Coriolis acceleration to detect rotation.

12. The system of claim 9, wherein the drive electronics applies a drive voltage to at least one motor drive comb which causes the at least one proof mass to oscillate.

13. The system of claim 9, wherein the noise is injected into the drive electronics after applying a system power source to the MEMS gyroscope.

14. The system of claim 9, wherein the noise is injected into the drive electronics substantially before the MEMS gyroscope reaches full power.

15. The system of claim 9, wherein the tuning fork frequency of the at least one proof mass is located substantially within a bandwidth of the noise.

16. The system of claim 15, wherein the bandwidth of the noise is substantially centered at the tuning fork frequency of the at least one proof mass.

17. The system of claim 15, wherein the bandwidth of the noise is substantially +/−

1000 Hertz wide.

18. A system for improving a start time of a MEMS gyroscope, comprising in combination:

a vibratory gyroscope operable to use a Coriolis acceleration to detect rotation;

drive electronics operable to apply a drive voltage to at least one motor drive comb which causes at least one proof mass to oscillate, and wherein the drive electronics locks onto substantially a tuning fork frequency of the at least one proof mass; and

a noise source that injects bandwidth limited white noise into the drive electronics until the drive electronics locks onto the tuning fork frequency of the at least one proof mass, wherein a bandwidth of the noise is substantially centered at a tuning fork frequency of the at least one proof mass, and wherein the bandwidth of the noise is substantially +/−

1000 Hertz wide.

19. The system of claim 18, wherein the noise is injected into the drive electronics after applying a system power source to the tuning fork gyroscope.

20. The system of claim 18, wherein the noise is injected into the drive electronics substantially before the tuning fork gyroscope reaches full power.