JPH08327366A - Vibration type gyro scope - Google Patents

Abstract

PURPOSE: To prevent a null voltage generated in a piezoelectric detection section in the driving of a vibrator from overlapping a detection output of Coriolis force as a noise. CONSTITUTION: Vibrators 10a, 10b, 10c are formed on an elastic body 10 in which piezoelectric material 12 is laminated on an elastic plate 11. When electric power is applied to electrodes 13, the vibrators 10b, 10c on both sides and the vibrator 10a in the central section are vibrated inversely to each other in X direction. Each of vibrators are vibrated in Z direction by the Coriolis force. The amplitude directions of the vibrators 10b, 10c on both sides and one 10a in the central section are reversed to each other. Polarization directions at a piezoelectric detection section are the same, then when the vibrators are deformed in the same directions, outputs having the same polarization are obtained. While null voltages are generated on detection electrodes 14a-14c by the distortion of the piezoelectric material 12 at a time when the vibrators are driven in the X direction, it is possible to cancel the null voltage by subtracting a detection output of the central vibrator 10a from the sum of detection outputs of vibrators 10b, 10c on both sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope for detecting the angular velocity of a rotary system, and in particular, reduces noise due to leakage output (null output) due to distortion of a piezoelectric detector to improve angular velocity detection accuracy. Vibration type gyroscope.

[0002]

2. Description of the Related Art Gyroscopes that detect rotational angular velocity are used in inertial navigation systems for aircraft and ships, but recently, they have been used in navigation systems for vehicles, attitude control of robots and unmanned vehicles, and even television cameras. It has also come to be used in screen shake prevention devices for video cameras and amusement-related devices.

As a gyroscope suitable for use in such various fields, a small one is required,
Therefore, a vibrating gyroscope is receiving attention. Figure 9
Shows a conventional example of this type of vibrating gyroscope.

In this vibrating gyroscope, a driving piezoelectric element 2 and a detecting piezoelectric element 3 are provided on the side surfaces of a columnar vibrator 1 made of a constant elastic metal (erinba) at right angles.
Are attached respectively. When the vibrator 1 is placed in a rotating system around the y-axis while the vibrator 1 is applied with bending vibration in the x-axis direction by the driving piezoelectric element 2, Coriolis force acts on the vibrator 1 in the z-axis direction. To do. The bending vibration of the vibrator 1 in the z-axis direction due to this Coriolis force is detected as voltage or current by the piezoelectric element 3.

The mass of the vibrator 1 is M, and the driving piezoelectric element 2 is
The vibration velocity of the vibrator 1 in the x-axis direction given by
(Vector value), the angular velocity around the y-axis is ω (vector value)
Then, Coriolis force F (vector value) is

[0006]

## EQU1 ## F = 2M (v0 × ω) (× is a vector product)

Therefore, the Coriolis force F is proportional to the angular velocity ω. The deformation vibration of the vibrator 1 in the z-axis direction due to this Coriolis force F is converted into a voltage by the detection piezoelectric element 3, and the angular velocity ω is obtained from this detection voltage.

[0008]

In the above vibrating gyroscope, the z-axis of the vibrator 1 is controlled by the piezoelectric element 3 for detection.
The vibration deformation in the direction is detected. That is, the voltage or current generated when the piezoelectric element 3 is flexed (distorted) in the z direction serves as a detection output for detecting the angular velocity ω.
However, when the vibrator 1 is vibrated in the x direction by the driving piezoelectric element 2, the detecting piezoelectric element 3 is distorted in the x direction, and the detecting piezoelectric element 3 is distorted in the x direction. Null voltage is generated. Since this null voltage is mixed with the voltage (the output for obtaining the angular velocity ω) due to the bending of the piezoelectric element 3 in the z direction, the null voltage leaks to the detection output from the piezoelectric element 3. The noise of the detection output from the piezoelectric element 3 increases.

In FIG. 10, the horizontal axis represents the angular velocity ω, and the vertical axis represents the amplitude (peak-to-peak value) of the vibration output detected by the piezoelectric element 3 for detection. As shown in Equation 1, the detection output at this time is proportional to the angular velocity ω. However, the leak output due to the null voltage is superimposed on the detection output. Due to the superposition of the leak output, the detection accuracy of the angular velocity ω was lowered.

As a means for reducing the noise due to the leakage output, a circuit for artificially generating a voltage corresponding to the null voltage is provided, and the circuit outputs the detection output from the piezoelectric element 3 in a pseudo manner. It is conceivable that the leak output is subtracted. However, such a noise reducing means requires a circuit for artificially generating a leakage output, which complicates the circuit structure of the device.

The present invention solves the above-mentioned problems of the prior art, and makes it possible to reduce or eliminate the leakage output due to the null voltage of the piezoelectric detector without providing a complicated circuit, and at the same time, to prevent the deformation due to the Coriolis force. It is an object of the present invention to provide a vibrating gyroscope capable of increasing detection output.

[0012]

A vibrating gyroscope according to the present invention comprises a plurality of vibrators formed separately in an elastic body through grooves, and driving means for vibrating the vibrators in directions opposite to each other. When a piezoelectric detector provided in each vibrator so that deformation of each vibrator in the same direction can be taken out as an output of the same polarity, and a vibrator vibrated by the driving means is placed in a rotating system. And a detection unit that extracts the vibration of each vibrator generated by the Coriolis force from the piezoelectric detection unit, and in the detection unit, a differential unit that takes a difference between outputs from the vibrators that vibrate in opposite directions is provided. It is characterized by being provided.

Alternatively, in the vibrating gyroscope of the present invention, the three oscillators formed separately in the elastic body through the groove, the pair of oscillators on both sides, and the oscillator in the center are in opposite directions. The driving means for vibrating the vibrator, the piezoelectric detector provided for each vibrator so that the deformation of each vibrator in the same direction can be taken out as the output of the same polarity, and the vibrator vibrated by the driving means is a rotating system. And a detection unit that extracts the vibration of each vibrator generated by the Coriolis force from the piezoelectric detection unit when placed on, in the detection unit, a unit that calculates the sum of the outputs from the vibrators on both sides, The present invention is characterized in that a differential means for calculating a difference between the output from the central oscillator and the sum of the outputs is provided.

In the above, it is preferable that the three vibrators have the same mass.

Alternatively, when the masses of the pair of vibrators on both sides are both m and the mass of the central vibrator is a times m, the sum of the outputs from the pair of vibrators on both sides is (1 / a ) Means for multiplying the output from the central oscillator and (1
It is also possible to configure so that the difference between the output multiplied by / a) is obtained by the differential means.

The elastic body is, for example, a flat plate of an elinvar. Grooves are formed in the flat plate of the elinvar to form a pair of vibrators or three vibrators, and each vibrator serves as driving means. The piezoelectric element for driving and the piezoelectric element for detection forming the piezoelectric detecting portion may be attached. Alternatively, the piezoelectric material is entirely adhered to a flat plate such as an elinvar, and the laminate of the elinvar and the piezoelectric material becomes an elastic body, and a part of this piezoelectric material becomes a piezoelectric element for driving vibration, and The other part may constitute the piezoelectric detector. Alternatively, the entire elastic body may be formed of a flat plate material of a piezoelectric material, and the piezoelectric material itself serves as a vibrator. In this case, a part of the piezoelectric material serving as the vibrator serves as a driving piezoelectric element, and the other part of the piezoelectric material serves as a detecting piezoelectric element.

[0017]

The present invention is one in which each of a plurality of vibrators is formed separately from an integral elastic body. The oscillators are vibrated in opposite directions (with opposite phases),
Further, the Coriolis force also vibrates in mutually opposite directions (in opposite phases). Then, the piezoelectric detector is configured to obtain detection outputs of the same polarity for all the vibrators when the vibrators vibrate in the same direction. Subtracting the outputs from the oscillators vibrating in the opposite direction,
The leakage outputs due to the null voltage generated in the piezoelectric detector during driving cancel each other out (see FIG. 5A). Therefore, the noise component can be removed from the detection output. Further, in the differential means for canceling the leakage output, as shown in FIG. 5B, the outputs from the vibrators vibrating in different phases due to the Coriolis force are added so as to have the same polarity.
That is, in the differential means, the detection output from each transducer is added, and at the same time, the leakage output is canceled.

Further, in the case where three (3) vibrators are formed in parallel on the elastic body, the pair of vibrators located on both sides are vibrated in the same phase, and the vibrator in the center is vibrated. Is oscillated in the opposite phase of the oscillator on both sides. That is, when the amplitude of the vibrators on both sides is in the −x direction at a certain time point, the amplitude of the center vibrator is in the + x direction. At this time,
Null voltage is obtained by finding the sum of the detection outputs from the piezoelectric detectors provided on both sides of the vibrator, and finding the difference between the detection outputs of the sum from the detection output from the piezoelectric detectors provided on the center vibrator. It is possible to cancel the leakage output due to, and it is also possible to add the detected values of the vibrations given to each vibrator by the Coriolis force with the same polarity.

In the case where the above-mentioned three vibrators are provided, when the masses of the three vibrators are all the same m, the absolute value of the average speed when the vibrators on both sides are driven is v Then, the absolute value V of the average speed when the central vibrator is driven is 2 × v. Therefore, by subtracting the sum of the detection outputs from the transducers on both sides from the detection output from the transducers in the center, it is possible to completely cancel the noise component due to the leakage output.

Further, when the mass of the vibrators on both sides is m and the mass of the vibrators on the center is a times m, and when the absolute value of the average speed of the vibrators on both sides is v, the vibrators on the center are The absolute value of the average velocity V of is (2 / a) · v. Therefore, the sum of the outputs from the piezoelectric detectors of the vibrators on both sides can be further calculated by (1 / a)
By multiplying and subtracting the output (1 / a) times from the detection output from the piezoelectric detecting unit of the central vibrator, it is possible to completely cancel the noise component due to the leakage output.

[0021]

1 is a plan view showing a vibrating gyroscope according to a first embodiment of the present invention, FIG. 2 is an enlarged end view in the direction of arrow II in FIG. 1, and FIG. 3 is a drive circuit D1 and a detection means (detection circuit). )
4 is a circuit block diagram of D2, and FIG. 4 is a perspective view illustrating a vibration mode of the vibration gyroscope.

The elastic body 10 of the vibration type gyroscope shown in FIGS. 1 and 2 is an elastic plate 1 made of a constant elastic material such as elinvar.
The piezoelectric materials 12 and 12 are laminated on both front and back surfaces of No. 1. The elastic body 10 made of this laminated body has grooves 10d, 1
Three vibrators (vibration plates) 10a, 10 separated by 0d
b and 10c. Each transducer 10a, 10b, 1
The width, length, and thickness of 0c are the same, and the vibrators 10a, 10b, and 10c have the same mass m.

The piezoelectric materials 12 and 12 are dielectrically polarized in the thickness direction, and the dielectric polarization direction of each part is
This is the direction indicated by the arrow in FIG. Each transducer 10a, 10
The drive electrodes 13 are laminated on the surfaces of the piezoelectric materials 12 and 12 at both widthwise edges of b and 10c.
A drive terminal A that supplies AC drive power to
The elastic plate 11 made of a constant elastic material is a common electrode, and this common electrode is grounded. A portion of the piezoelectric material 12, 12 on which the drive electrode 13 is formed is a driving piezoelectric vibrator (a) that constitutes a driving means.

When AC drive power is applied to each drive electrode 13 via the terminal A, the left and right vibrators 10b and 10c are formed.
And the vibrator 10a at the center have different phases in the plate surface direction (x
Direction). At some point, both transducers 10b
And the amplitude direction of 10c is + x direction, the center oscillator 1
The amplitude direction of 0a is the −x direction.

Elastic body 10 of this vibrating gyroscope
Is placed in a rotary system centered on the Y axis, the Coriolis force causes vibrations in the z direction in the respective vibrators 10a, 10b, 10c. As shown in FIG. 4, the oscillators 10b and 10c on both the left and right sides and the oscillator 10a at the center have different phases of vibration, and when the amplitude direction of the oscillators 10b and 10c is −z direction at a certain point, the oscillation at the center is performed. The amplitude direction of the child 10a is the + z direction.

In the present invention, as shown in FIG. 4, the vibration component when vibrating in the z direction is detected from the piezoelectric materials 12, 12. For this detection, each transducer 10a, 10b, 1
Detection electrodes 14a, 14b, and 14c are formed on the front and back surfaces of the piezoelectric materials 12 and 12 at the center portion in the width direction of 0c, respectively. The detection terminals of the detection electrodes 14a, 14b, 14c are indicated by B1, B2, B3.

In this elastic body, each vibrator 10
a, 10b, 10c, the detection electrodes 14a, 14
The part where b and 14c are formed is the piezoelectric detection part (b).
Is. As shown in FIG. 2, each transducer 10a, 10b,
In the piezoelectric detector (b) 10c, the dielectric polarizations of the piezoelectric materials 12 and 12 are all in the same leftward direction in the drawing. Therefore, when each transducer 10a, 10b, 10c is distorted in the same direction,
The polarities of the detection voltage or the detection current obtained from the piezoelectric detectors (b) of the vibrators 10a, 10b, and 10c are the same.

That is, when the vibrator 10a is bent in the + z direction, when the vibrator 10b is bent in the + z direction, and when the vibrator 10c is bent in the + z direction, each detection terminal B is detected.
The polarities of the detection voltage or the detection current obtained at 1, B2 and B3 are the same. In addition, when the vibrator 10a is deformed in the + x direction and when the vibrator 10b is deformed in the + x direction,
When the vibrator 10c is deformed in the + x direction, the detection electrode and each detection terminal B1, B2 in each piezoelectric detection unit (b)
All the leak outputs such as the null voltage extracted from B3 have the same polarity.

In the circuit shown in FIG. 3, the drive circuit D1 is provided with a high frequency oscillation circuit 21, and from this high frequency oscillation circuit 21, AC drive power is applied to the drive terminal A shown in FIG. In the detection means (detection circuit) D2, the detection terminal B2 of the detection electrode 14b provided on the vibrators 10b and 10c located on both sides of the three (three) vibrators, and the detection electrode 1
A summing circuit (adding means) 22 for obtaining the sum of the detection outputs of the detection terminals B3 of 4c is provided. Further, a differential circuit (differential means, subtraction means) 23 for subtracting the output from the summing circuit 22 from the detection output from the detection electrode 14a (detection terminal B1) provided on the central oscillator 10a is provided. ing. The output from the differential circuit 23 is detected by the synchronous detection circuit 24, and the synchronization signal (reference signal) for this detection is given from the oscillation circuit 21. The output synchronously detected by the synchronous detection circuit 24 becomes the detection output.

Next, the operation of the vibrating gyroscope will be described. The frequency of the high frequency signal generated by the oscillator circuit 21 shown in FIG.
It substantially coincides with the resonance point or anti-resonance point of vibration of 10c in the ± x directions. This high-frequency signal is applied as AC drive power from the drive terminal A to the drive electrodes 13 on both front and back surfaces of the elastic body 10 at the same time.

As shown by the arrows in FIG. 2, the vibrators 10b and 10c on both the left and right sides have the same dielectric polarization direction of the driving piezoelectric vibrator (a), but the vibrator 1 at the center.
In 0a, the dielectric polarization directions of the driving piezoelectric vibrator (a) are symmetrical with the dielectric polarization directions of the vibrators 10b and 10c in the vertical direction in FIG. By inputting AC driving power to the driving electrode 13, the driving piezoelectric vibrator (a) expands or contracts, and each vibrator 10a, 1
Oscillation is driven so that 0b and 10c are deformed in the x direction.

As described above, in the part (a) of each vibrator, the dielectric polarization directions of the ones on both sides and the one in the center are different, so that the oscillators 10b and 10c on both sides and the oscillator 10a in the center are different. , The phase of vibration in the x direction is different by 180 degrees, and the vibrators 10b and 10c on both sides and the vibrator 10a in the center are different.
The vibration direction of is opposite. Transducer 1 on both sides at some point
When the amplitudes of 0b and 10c are in the + x direction, the central oscillator 1
The amplitude of 0a is in the -x direction.

When the vibrators 10a, 10b, 10c are oscillated in the x direction and placed in a rotary system centered on an axis parallel to the y axis, the vibrators 10a, 10b, 10c are caused by Coriolis force.
The a, 10b and 10c are vibrated in the z direction which is a direction orthogonal to the x direction which is the driving direction. Transducer 1 on both sides
0b and 10c and the central oscillator 10a have opposite phases of vibrations in the driving direction (x direction), so that the vibrations given by the Coriolis force also vibrate on both sides of the vibrators 10b and 10c.
And the central oscillator 10a are in opposite directions. That is, as shown in FIG. 4, when the amplitude of the vibration due to the Coriolis force of the vibrators 10b and 10c on both sides is −z direction, the amplitude of the central vibrator 10a is + z direction.

The detection output of the voltage or current generated by the distortion of each of the vibrators 10a, 10b, 10c is obtained from each of the detection terminals B1, B2, B3. As shown in FIG.
Detection outputs obtained from the detection terminals B2 and B3 on both sides are added by a summing circuit (adding means) 22. Further, in the differential circuit (subtraction means) 23, the central detection terminal B1
The sum output is subtracted from the detection output of.

Here, in the above embodiment, the three vibrators 1
The masses of 0a, 10b, and 10c are all the same m. Figure 6
Shows the mass of each transducer 10a, 10b, 10c schematically in a mass system. Each transducer 10a, 10
The average speed when the b and 10c are driven to vibrate in the x direction is set to -V at the central vibrator 10a, and the vibrators 1 on both sides are
It is + v at 0b and 10c. Each oscillator 10
Since a, 10b, and 10c operate in one elastic body 10 which is regarded as one mass system, the relationship between the mass and velocity of each oscillator in the mass system is expressed by the following mathematical formula 2 according to the law of energy conservation. As shown in.

[0036]

[Formula 2] m · V−2m · v = 0 V−2v = 0

That is, each transducer 10a, 10b, 10
When c vibrates in the x direction, the vibrators 10b on the left and right sides,
When the absolute value of the average velocity of 10c is v, the absolute value V of the average velocity of the central transducer 10a is twice the above v.

When AC drive power is applied to the drive terminal A and the vibrators 10a, 10b, 10c vibrate in the x direction,
A strain in the x direction is applied to the piezoelectric material of each piezoelectric detector (b), and this strain causes the detection electrodes 14a, 14b, 14c.
Null voltage occurs. At this time, the null voltage of the piezoelectric detector (b) is proportional to the speed in the x direction, and the null voltage detected at each of the detection terminals B2 and B3 on both sides is at the central detection terminal B1. The detected null voltage has a doubled value. By the summing circuit 22 of FIG. 3, the null voltages of the detection electrodes 14b and 14c on both sides are added and doubled, and in the differential circuit 23, from the null voltage obtained from the central detection electrode 14a, The doubled null voltage is subtracted. Therefore, as shown in FIG. 5 (A), in the signal sent to the synchronous detection circuit 24, the noise of the leakage output due to the null voltage is completely eliminated in calculation.

Next, when the vibrators 10a, 10b and 10c vibrate in the z direction by the Coriolis force, the piezoelectric detector (b)
A detection voltage or current due to the bending (distortion) of the piezoelectric material in the z direction is obtained. Each transducer 10a, 10b,
In 10c, the direction of dielectric polarization in the piezoelectric detector (b) is the same. Further, the oscillators 10b and 10c on both sides and the oscillator 10a at the center have a phase difference of 180 degrees in the z-direction. Therefore, in the detection of vibration in the z direction due to the Coriolis force, the detection electrodes 14b and 14c on both sides and the detection electrode 14a in the center always have opposite detection output polarities.

Further, as shown in the equation 1, each oscillator 10
The Coriolis force acting on a, 10b, and 10c is proportional to the speed of each transducer when driven in the x direction. When the masses of the vibrators 10a, 10b, and 10c are both m, as shown in Equation 2, when the absolute value of the average velocity in the x direction given to the vibrators 10b and 10c on both sides is v, The absolute value V of the average velocity in the x direction given to the oscillator 10a is 2 × v. Therefore, the detection output of the Coriolis force is twice the absolute value and the polarity is opposite to the detection output of the vibrators 10b or 10c on both sides of the detection output.

Therefore, the summing circuit 22 obtains the sum of the detection outputs from the detection terminals B2 and B3 on both sides, and the differential circuit 23
By subtracting the sum output from the detection output from the detection terminal B1, the Coriolis force detection output is obtained by adding those detected by each transducer, as shown in FIG. 5B. Can be obtained as

That is, each transducer 10a, 10b, 10
In the piezoelectric detection unit (b) of c, it is assumed that the detection electrodes 14a, 14b, and 14c of all the vibrators can output the same polarity if the vibration directions are the same, and the summing circuit 22 and the differential circuit 22 By providing the circuit 23, the noise of the leak output due to the null voltage can be canceled out, and the Coriolis force can be detected as a sufficiently large sum of the detection outputs from the vibrators.

Next, in the elastic body 10 of the vibration type gyroscope having the structure shown in FIGS. 1 and 2, the masses of the vibrators 10b and 10c on the left and right sides are m, and the mass of the center vibrator 10a is m. The case of doubling will be described. At this time, Formula 3 is established by the law of energy conservation in the elastic body 10 which is one mass system.

[0044]

[Formula 3] a · m · V−2m · v = 0 V− (2 / a) · v = 0

That is, the absolute value V of the average velocity of the vibration of the central oscillator 10a in the x direction is (2/2 /) of the absolute value v of the average velocity of the vibration of the oscillators 10b and 10c on both sides in the x direction.
a) Double. The detection output by the null voltage and Coriolis force detected from the detection electrodes 14a, 14b, 14c is
As described above, it is proportional to each speed driven in the x direction. Therefore, in the detecting means D of FIG. 3, an amplifier 25 for multiplying the detection voltage or the detection current by (1 / a) is provided in the next stage of the summing circuit 22, and the amplifier 25 outputs the summing output by (1 / a). ), And by applying this to the differential circuit 23, the null voltage can be completely canceled in calculation, and the Coriolis force detection output can be increased.

When the oscillators 10b and 10c on both sides and the oscillator 10a in the center have different masses, it is possible to cancel the null voltage, although not completely, without the amplifier 25. It is possible to obtain the effect of reducing noise due to leakage output.

7 and 8 show an elastic body 30 according to the second embodiment of the present invention. This elastic body 30 is formed by laminating a piezoelectric material on one side or both sides of an elastic plate of a constant elastic material, as in the embodiment shown in FIGS. 1 and 2, for example. A groove 30c is formed at the center of the elastic body 30, and the elastic body 30 is separated into two plate-shaped vibrators 30a and 30b. The combination of the dielectric polarization directions of the piezoelectric materials of the respective vibrators 30a and 30b and the arrangement of the electrodes are the same as those of the vibrators 10a and 10c shown in FIG. That is, the dielectric polarization direction of the piezoelectric material and the arrangement of each electrode are as shown in FIG.
0a corresponds to the vibrator 30a, and the vibrator 10c corresponds to the vibrator 30b. Therefore, in the piezoelectric detector (b), both transducers 30a and 30b can obtain outputs of the same polarity by deformation in the same z direction.

In the detection means (detection circuit) of this embodiment,
The detection output from the detection electrode of the vibrator 30a and the vibrator 30a
A differential circuit (subtraction means) for obtaining the difference from the detection output from the detection electrode of b is provided. The central portion of the base end of the elastic body 30 is supported by the support rod 31.

As shown in FIG. 8A, both diaphragms 30a and 30b are driven in a phase different by 180 degrees in the x direction by the AC driving power supplied to the driving electrodes. When placed in a rotating system centered on the y-axis direction, as shown in FIG. 8 (B), both oscillators 30a and 30b are separated by Coriolis force.
It is oscillated with a phase difference of 180 degrees in the z direction. Taking the differential of the detection output from the detection electrodes cancels out the null voltage when the vibrators 30a and 30b vibrate in the x direction, as shown in FIG. Similarly to the case shown in B), the detection outputs from both transducers 30a and 30b are added as the same polarity, and the angular velocity can be detected at a high output.

[0050]

As described above, in the present invention, when the piezoelectric vibrator is driven by the driving means, the null voltage taken out from the piezoelectric detector is canceled by each vibrator,
Reduced or eliminated. Therefore, it is possible to reduce the noise component of the leakage output that is superimposed on the detection output. Further, in the detection of the vibration due to the Coriolis force, the detection outputs obtained for the respective vibrators are added with the same polarity, and the angular velocity can be detected with high sensitivity.

[Brief description of drawings]

FIG. 1 is a plan view showing an elastic body of a vibrating gyroscope according to a first embodiment of the present invention,

FIG. 2 is an enlarged end view showing the elastic body shown in FIG. 1 from a direction II.

FIG. 3 is a block diagram showing a circuit configuration of a vibrating gyroscope,

FIG. 4 is a perspective view illustrating a vibration mode of each vibrator,

5A is an explanatory diagram of a waveform of a null voltage, FIG. 5B is an explanatory diagram of a waveform of a detection output by Coriolis force,

FIG. 6 is a schematic diagram in which each oscillator is represented by a mass system,

FIG. 7 is a perspective view showing an elastic body of a vibrating gyroscope according to a second embodiment of the invention.

8A and 8B are explanatory views of vibration modes of the elastic body according to the second embodiment,

FIG. 9 is a perspective view showing an elastic body of a conventional vibrating gyroscope,

FIG. 10 is a diagram showing a relationship between angular velocity and detection output in a conventional vibration gyroscope.

[Explanation of symbols]

 10 Elastic body of vibration type gyroscope 10a, 10b, 10c Transducer 10d Groove 11 Elastic plate 12 Piezoelectric material 13 Drive electrode 14a, 14b, 14c Detection electrode 21 Oscillation circuit 22 Summing circuit 23 Differential circuit 25 Amplifier 30 Elastic body 30a , 30b Transducer (a) Piezoelectric oscillator for driving (b) Piezoelectric detector

Claims (4)

[Claims] 1. A plurality of vibrators formed separately in an elastic body through grooves, driving means for vibrating the vibrators in mutually opposite directions, and the same deformation of each vibrator in the same direction. A piezoelectric detector provided on each vibrator so that it can be taken out as a polar output, and a vibration of each vibrator generated by Coriolis force when the vibrator vibrated by the driving means is placed in a rotating system A vibrating gyroscope, characterized in that it has a detecting means taken out from a piezoelectric detecting portion, and the detecting means is provided with a differential means for obtaining a difference between outputs from vibrators vibrating in mutually opposite directions. . 2. A vibrating member, which is formed on an elastic body and is separated from each other through a groove, a driving unit which vibrates a pair of vibrating members on both sides and a vibrating member at the center in mutually opposite directions, Coriolis force when a piezoelectric detector provided in each vibrator so that deformation of the vibrator in the same direction can be taken out as an output of the same polarity, and the vibrator vibrated by the driving means is placed in the rotating system. And a detection unit that extracts the vibration of each vibrator generated by the piezoelectric detection unit from the piezoelectric detection unit, wherein the detection unit calculates a sum of outputs from the vibrators on both sides and an output from the center vibrator. And a differential means for calculating a difference from the sum of the outputs, and a vibrating gyroscope. 3. The vibrating gyroscope according to claim 2, wherein the three oscillators have the same mass. 4. When the masses of the pair of vibrators on both sides are both m and the mass of the center vibrator is a times m, the sum of the outputs from the pair of vibrators on both sides is (1 / a 3. The vibrating gyroscope according to claim 2, wherein means for multiplying is provided, and the difference between the output from the central oscillator and the output multiplied by (1 / a) is obtained by the differential means.