Vibrating gyroscope and electronic device using the same

• US 20020017135A1
• Filed: 06/25/2001
• Published: 02/14/2002
• Est. Priority Date: 06/27/2000
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kumada, Akira, Mori, Akira, Ebara, Kazuhiro
• Granted Patent: US 6,666,090 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5649 Signal processing

Abstract

A vibrating gyroscope includes a vibrator having a driving electrode and a sensor electrode, a driving circuit for applying a driving voltage to the driving electrode, a detection circuit which receives, from the sensor electrode, a signal corresponding to a bending displacement of the vibrator, a signal processing circuit for processing a signal input from the detection circuit to detect an angular velocity, a power supply circuit, and a diagnostic circuit for examining whether or not the detection circuit, the driving circuit, the signal processing circuit, and the power supply circuit are all functioning normally.

Claims

1. A vibrating gyroscope comprising:

a vibrator having a driving electrode and a sensor electrode;

a driving circuit for applying a driving voltage to the driving electrode;

a sensor circuit which receives a signal corresponding to a bending displacement of said vibrator from the sensor electrode;

a signal processing circuit for processing a signal input from said sensor circuit to sense an angular velocity; and

a diagnostic circuit responsive to signals from said driving circuit, said sensor circuit and said signal processing circuit for examining whether or not said sensor circuit, said driving circuit, and said signal processing circuit are all functioning normally.

2. A vibrating gyroscope according to claim 1, wherein said signal processing circuit includes a switching device and a detector,

the switching device being adapted to output to said detector one of a signal input from said sensor circuit and a signal input from said driving circuit,

the detector being adapted to detect a signal input from the switching device in synchronization with the driving voltage;

and

said signal processing circuit sensing an angular velocity in response to an input of the signal from said sensor circuit through the switching device, and outputting a signal indicating whether or not said signal processing circuit has an abnormality in response to the signal from said driving circuit through the switching device.

3. A vibrating gyroscope according to claim 1, wherein said diagnostic circuit further includes:

a first rectifier circuit for rectifying a signal input from said sensor circuit;

a second rectifier circuit for rectifying a signal input from said driving circuit;

an adder circuit for adding the signal rectified by said first rectifier circuit and the signal rectified by said second rectifier circuit; and

a first determination unit for determining whether or not the resultant signal from said adder circuit falls within a predetermined range.

4. A vibrating gyroscope according to claims 1, 2 or 3, wherein said diagnostic circuit includes a second determination unit for comparing an input power supply voltage with a reference voltage to determine whether or not the power supply voltage falls within a predetermined range.

5. An electronic device including a vibrating gyroscope according to claims 1, 2 or 3.

6. An electronic device including a vibrating gyroscope according to claim 4.

7. A vibrating gyroscope according to claim 1, wherein said diagnostic circuit includes a sensor determination circuit for determining whether said sensor circuit is functioning normally, a driving determination circuit for determining whether said driving circuit is functioning normally;

a single processing determination circuit for determining whether said signal processing circuit is functioning normally;

a power supply determination circuit for determining whether an input power supply voltage falls within a predetermined range; and

a comprehensive determination circuit responsive to the sensor determining circuit, the driving determination circuit, the signal processing determination circuit, and the power supply determination circuit for outputting a signal and indicating whether the sensor determination circuit, the driving determination circuit, the signal processing determination circuit or the power supply power determination circuit are functioning normally.

8. A vibrating gyroscope according to claim 7, wherein the sensor determination circuit includes a first rectifier, a first smoothing circuit and a first comparator, the sensor circuit being connected to the first rectifier circuit, the first rectifier circuit being connected to the first smoothing circuit, the first smoothing circuit being connected to the first comparator, and the first comparator being connected to the comprehensive determination circuit.

9. A vibrating gyroscope according to claim 7, wherein the driving determination circuit includes a second rectifier circuit, a second smoothing circuit and a second comparator, the driving circuit being connected to the second rectifier circuit, the second rectifier circuit being connected to the second smoothing circuit, the second smoothing circuit being connected to the second comparator, and the second comparator being connected to the comprehensive determination circuit.

10. A vibrating gyroscope according to claim 8, wherein the driving determination circuit includes a second rectifier circuit, a second smoothing circuit and a second comparator, the driving circuit being connected to the second rectifier circuit, the second rectifier circuit being connected to the second smoothing circuit, the second smoothing circuit being connected to the second comparator, and the second comparator being connected to the comprehensive determination circuit.

11. A vibrating gyroscope according to claim 7, wherein the signal processing determination circuit includes a third rectifier circuit, a third smoothing circuit and a third comparator, the signal processing circuit being connected to the third rectifier, the third rectifier circuit being connected to the third smoothing circuit, the third smoothing circuit being connected to the third comparator and the third comparator being connected to the comprehensive determination circuit.

12. A vibrating gyroscope according to claim 10, wherein the signal processing determination circuit includes a third rectifier circuit, a third smoothing circuit and a third comparator, the signal processing circuit being connected to the third rectifier, the third rectifier circuit being connected to the third smoothing circuit, the third smoothing circuit being connected to the third comparator and the third comparator being connected to the comprehensive determination circuit.

13. A vibrating gyroscope according to claim 12, wherein the power supply determination circuit includes a fourth comparator for comparing whether the input power supply voltage falls within the predetermined ranges.

14. A vibrating gyroscope according to claim 1, wherein the diagnostic circuit further includes a sensor/driving determination circuit, which includes the sensor circuit, the driver circuit, first and second rectifier circuits, first and second smoothing circuits, an adder circuit and a comparator, the first rectifier circuit being connected to the first sensor circuit and the first smoothing circuit and the second rectifier circuit being connected to the driving circuit and the second smoothing circuit, the first and second smoothing circuits being connected to the adder circuit and the adder circuit being connected to the comparator.

15. A vibrating gyroscope according to claim 2, wherein the signal processing circuit further includes first and second resistors, one end of the first resistor being connected to a first input terminal of the switching device which receives the signal input from the sensor circuit and another end of the first resistor being connected to a second input terminal of the switching device, which receives the signal input from the driving circuit, one end of the second resistor being connected to the second input terminal of the switching device and another end of the second resistor being connected to the driving circuit.

16. A vibrating gyroscope according to claim 1, wherein said signal processing circuit includes a detector, a reference voltage circuit and first and second switching devices, the reference voltage circuit outputting a predetermined constant voltage and the first switching device inputting to the detector a signal output from the sensor circuit or the signal output from the reference voltage circuit, and the second switching device inputting to the detector either the signal output from the reference voltage circuit or the single output from the driving circuit.

17. A vibrating gyroscope according to claim 3, wherein said diagnostic circuit includes a second determination unit for comparing an input power supply voltage with a reference voltage to determine whether or not the power supply voltage falls within a predetermined range.

18. A vibrating gyroscope according to claim 17, wherein said diagnostic circuit further includes:

a first rectifier circuit for rectifying a signal input from said sensor circuit;

a second rectifier circuit for rectifying a signal input from said driving circuit;

an adder circuit for adding the signal rectified by said first rectifier circuit and the signal rectified by said second rectifier circuit; and

a first determination unit for determining whether or not the resultant signal from said adder circuit falls within a predetermined range.

19. An electronic device including a vibrating gyroscope according to any one of claims 13 to 17.