Integrated low power digital gyro control electronics

• US 6,915,215 B2
• Filed: 06/25/2003
• Issued: 07/05/2005
• Est. Priority Date: 06/25/2002
• Status: Active Grant

• Current Assignee: California Institute of Technology, The Boeing Co., Regents of the University of California (University of California)
• Original Assignee: California Institute of Technology, The Boeing Co., Regents of the University of California (University of California)
• Inventors: Hayworth, Ken J., M'Closkey, Robert, Grayver, Eugene, Challoner, A. Dorian
• Primary Examiner(s): Hoff, Marc S.
• Assistant Examiner(s): Raymond, Edward
• Application Number:
  US10/603,557
• Publication Number:
  US 20040088127A1
• Time in Patent Office: 741 Days
• Field of Search: 702/32, 702/145, 702/147, 735/041.2, 735/041.4, 735/041.6
• US Class Current: 702/32
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces

Abstract

Embodiments of the invention generally encompass a digital, application specific integrated circuit (ASIC) has been designed to perform excitation of a selected mode within a vibratory rate gyroscope, damping, or “force-rebalance,” of other modes within the sensor, and signal demodulation of the in-phase and quadrature components of the signal containing the angular rate information. The ASIC filters dedicated to each channel may be individually programmed to accommodate different rate sensor designs/technology or variations within the same class of sensors. The ASIC architecture employs a low-power design, making the ASIC, particularly suitable for use in power-sensitive applications.

Claims

1. A circuit device comprising:

a digital drive controller circuit for producing a drive signal for exciting a drive mode of a vibratory gyroscope to a substantially constant amplitude from a drive mode response signal;

a digital rebalance controller circuit for producing a sense rebalance signal from a sense mode response signal to regulate a sense mode of the vibratory gyroscope to substantially zero; and

a digital demodulator for demodulating the sense rebalance signal with the drive mode response signal to produce a digital rate estimate of the vibratory gyroscope;

wherein the digital drive controller circuit, digital rebalance controller circuit and digital demodulator comprise a distributed digital control circuit.

2. The circuit device of claim 1, wherein the digital drive controller circuit, the digital rebalance controller circuit and the digital demodulator are implemented on a single application specific integrated circuit (ASIC).

3. The circuit device of claim 1, wherein the drive mode response signal and the sense mode response signal are combined separately in the digital drive controller circuit and in the digital rebalance controller circuit to aid in isolating the drive and sense modes.

4. The circuit device of claim 3, wherein the drive mode response signal and the sense mode response signal are combined separately in the digital drive controller circuit and in the digital rebalance controller circuit each with a pair of programmable amplifiers.

5. The circuit device of claim 3, wherein the drive mode response signal and the sense mode response signal are combined separately in the digital drive controller circuit and in the digital rebalance controller circuit each with a pair of programmable filters.

6. The circuit device of claim 1, wherein the drive signal and the sense rebalance signal are combined separately to excite the drive mode and regulate the sense mode to aid in isolating the drive and sense mode.

7. The circuit device of claim 6, wherein the drive signal and the sense rebalance signal are combined with a separate pair of programmable amplifiers to each excite the drive mode and regulate the sense mode.

8. The circuit device of claim 6, wherein the drive signal and the sense rebalance signal are combined with a separate pair of programmable filters to each excite the drive mode and regulate the sense mode.

9. The circuit device of claim 1, wherein the digital drive controller circuit comprises an automatic gain control for exciting the drive mode to the substantially constant amplitude.

10. The circuit device of claim 1, wherein the digital drive controller circuit and the digital rebalance controller circuit are programmable to match the vibratory gyroscope.

11. The circuit device of claim 10, wherein the programmable digital drive controller circuit and the programmable digital rebalance controller circuit each comprise one or more programmable finite impulse response (FIR) filters programmed to match the vibratory gyroscope.

12. The circuit device of claim 10, wherein the programmable digital drive controller circuit and the programmable digital rebalance controller circuit comprise one or more programmable amplifiers.

13. The circuit device of claim 12, wherein the one or more programmable amplifiers comprise a pair of programmable amplifiers, each pair programmed to combine separately the drive mode response signal and the sense mode response signal in the digital drive controller circuit and in the digital rebalance controller circuit to aid in isolating the drive and sense modes.

14. The circuit device of claim 12, wherein the one or more programmable amplifiers comprise a pair of programmable amplifiers, each pair programmed to combine separately the drive signal and the sense rebalance signal to excite the drive mode and regulate the sense mode to aid in isolating the drive and sense modes.

15. The circuit device of claim 1, wherein the digital-drive controller circuit comprises an automatic gain control for exciting the drive mode to the substantially constant amplitude and the programmable digital drive controller circuit and the programmable digital rebalance controller circuit each comprise one or more programmable finite impulse response (FIR) filters programmed to match the vibratory gyroscope;

wherein the drive mode response signal and the sense mode response signal are combined separately in the digital drive controller circuit and in the digital rebalance controller circuit each with a pair of programmable amplifiers and the drive signal and the sense rebalance signal are combined with a separate pair of programmable amplifiers to each excite the drive mode and regulate the sense mode; and

wherein the digital drive controller circuit, the digital rebalance controller circuit and the demodulator are implemented on a single application specific integrated circuit (ASIC).

16. A method of operating a vibratory gyroscope comprising the steps of:

producing a drive signal for exciting a drive mode of a vibratory gyroscope with a digital drive controller circuit to a substantially constant amplitude from a drive mode response signal;

producing a sense rebalance signal from a sense mode response signal with a digital rebalance controller circuit to regulate a sense mode of the vibratory gyroscope to substantially zero; and

demodulating the sense rebalance signal with the drive mode response signal using a demodulator to produce a digital rate estimate of the vibratory gyroscope;

wherein the digital drive controller circuit, digital rebalance controller circuit and digital demodulator comprise a distributed digital control circuit.

17. The method of claim 16, wherein the digital drive controller circuit, the digital rebalance controller circuit and the demodulator are implemented on a single application specific integrated circuit (ASIC).

18. The method of claim 16, further comprising combining separately the drive mode response signal and the sense mode response signal in the digital drive controller circuit and in the digital rebalance controller circuit to aid in isolating the drive and sense modes.

19. The method of claim 18, further comprising combining separately the drive mode response signal and the sense mode response signal in the digital drive controller circuit and in the digital rebalance controller circuit each with a pair of programmable amplifiers.

20. The method of claim 18, further comprising combining separately the drive mode response signal and the sense mode response signal in the digital drive controller circuit and in the digital rebalance controller circuit each with a pair of programmable filters.

21. The method of claim 16, further comprising combining separately the drive signal and the sense rebalance signal to excite the drive mode and regulate the sense mode to aid in isolating the drive and sense mode.

22. The method of claim 21, further comprising combining separately the drive signal and the sense rebalance signal with a separate pair of programmable amplifiers to each excite the drive mode and regulate the sense mode.

23. The method of claim 21, further comprising combining separately the drive signal and the sense rebalance signal with a separate pair of programmable filters to each excite the drive mode and regulate the sense mode.

24. The method of claim 16, wherein the digital drive controller circuit comprises an automatic gain control for exciting the drive mode to the substantially constant amplitude.

25. The method of claim 16, wherein the digital drive controller circuit and the digital rebalance controller circuit are programmable to match the vibratory gyroscope.

26. The method of claim 25, wherein the programmable digital drive controller circuit and the programmable digital rebalance controller circuit each comprise one or more programmable finite impulse response (FIR) filters programmed to match the vibratory gyroscope.

27. The method of claim 25, wherein the programmable digital drive controller circuit and the programmable digital rebalance controller circuit comprise one or more programmable amplifiers.

28. The method of claim 27, wherein the one or more programmable amplifiers comprise a pair of programmable amplifiers, each pair programmed to combine separately the drive mode response signal and the sense mode response signal in the digital drive controller circuit and in the digital rebalance controller circuit to aid in isolating the drive and sense modes.

29. The method of claim 27, wherein the one or more programmable amplifiers comprise a pair of programmable amplifiers, each pair programmed to combine separately the drive signal and the sense rebalance signal to excite the drive mode and regulate the sense mode to aid in isolating the drive and sense modes.

30. The method of claim 16, wherein the drive loop comprises an automatic gain control for exciting the drive mode to the substantially constant amplitude and the programmable drive loop and the programmable rebalance loop each comprise one or more programmable finite impulse response (FIR) filters programmed to match the vibratory gyroscope;

wherein the drive mode response signal and the sense mode response signal are combined separately in the drive loop and in the rebalance loop each with a pair of programmable amplifiers and the drive signal and the sense rebalance signal are combined with a separate pair of programmable amplifiers to each excite the drive mode and regulate the sense mode; and

wherein the drive loop, the rebalance loop and the demodulator are implemented on a single application specific integrated circuit (ASIC).