Self-diagnosing circuit for vibrating gyroscope

• US 6,588,274 B1
• Filed: 10/26/2000
• Issued: 07/08/2003
• Est. Priority Date: 10/29/1999
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Mori, Akira, Kumada, Akira, Ebara, Kazuhiro
• Primary Examiner(s): Larkin, Daniel S.
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US09/697,412
• Time in Patent Office: 985 Days
• Field of Search: 735/040.2, 735/041.2, 735/041.6, 73/13.7, 73/13.8, 735/140.2, 735/141.6, 735/040.4, 735/040.3, 73/17.7, 73/17.9, 73/18.2
• US Class Current: 73/504.02
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces

Abstract

A self-diagnosing circuit for a vibrating gyroscope for detecting a vibration due to a Coriolis force including a differential operating circuit for determining a difference between output signals outputted from a plurality of detecting electrodes which provided on the vibrator to detect the vibration due to the Coriolis force; and an offset signal source for superposing an offset signal on at least one of the signals outputted from said plurality of detecting electrodes such that the signals are offset with different signal levels.

Claims

1. A self-diagnosing circuit for a vibrating gyroscope having a vibrator for detecting a vibration due to a Coriolis force, comprising:

differential operating means for determining a difference between output signals outputted from a plurality of detecting means which are provided on the vibrator to detect the vibration due to the Coriolis force; and

an offset signal source for superposing an offset signal on at least a first one of the signals outputted from said plurality of detecting means such that the signals are offset with different signal levels;

further comprising signal detection means for detecting the presence or absence of a signal component caused by an offset signal included in an output signal of said differential operating means; and

based on the presence or absence of said signal component, determines a state of a detecting means on the vibrator.

2. A self-diagnosing circuit for a vibrating gyroscope according to claim 1, further comprising:

an additional offset signal source for superposing an offset signal on a second one of the signal outputted from said plurality of detecting means such that the signals are offset with different signal levels.

3. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 2, wherein the offset signal source and the additional signal source are each voltage signal sources.

4. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 3, wherein the offset voltage signal source and the additional offset voltage signal source are each DC voltage signal sources.

5. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 3, wherein the offset voltage signal source and the additional offset voltage signal source are each AC voltage signal sources.

6. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 2, wherein the offset signal source and the additional offset signal source are each current signal sources.

7. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 6, wherein the offset current signal source and the additional offset current signal source are each DC current signal sources.

8. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 6, wherein the offset current signal source and the additional offset current signal source are each AC current signal sources.

9. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 2, wherein the offset signal source and the additional signal source have different values.

10. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 1 or claim 2, further comprising signal detecting means for detecting the presence or absence of a signal component caused by an offset signal included in an output signal of said difference operating means.

11. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 1, wherein said signal detecting means includes an analog-to-digital converter responsive to the output signal of said differential operating means to convert said signal into a digital signal.

12. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 11, further including a processing unit responsive to the output of said analog-to-digital converter for detecting the presence or absence of the signal component caused by an offset signal included in an output signal of said differential operating means.

13. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 1, wherein the signal detecting means includes a wave detection circuit operated in synchronism with the offset and additional offset signal sources.

14. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 1, wherein said offset signal source includes a voltage signal source for outputting an offset voltage as an offset signal.

15. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 14, wherein the voltage signal source is a DC signal source.

16. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 14, wherein the voltage signal source is an AC signal source.

17. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 1, wherein said offset signal source includes a current signal source for outputting an offset current as an offset signal.

18. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 17, wherein the current signal source is a DC current signal source.

19. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 18, wherein said current signal source is an AC current signal source.

20. A self-diagnosing circuit for a vibrating gyroscope as claimed in claim 1 or claim 2, further including means for detecting a failure based on an output voltage and the phase thereof of said differential operating means.

21. A self-diagnosing circuit for a vibrating gyroscope having a vibrator for detecting a vibration due to a Coriolis force, comprising:

a differential operating circuit for determining a difference between output signals outputted from a plurality of detecting electrodes which are provided on the vibrator to detect the vibration due to the Coriolis force; and

an offset signal source for superposing an offset signal on at least a first one of the signals outputted from said plurality of detecting electrodes such that the signals are offset with different signal levels;

further comprising a signal detector detecting the presence or absence of a signal component caused by an offset signal included in an output signal of said differential operating circuit, and based of the presence or absence of said signal component, determines a state of detecting electrode on the vibrator.