JP2003014465A - Vibration type gyroscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration type gyroscope having a stabilized support and an excellent vibration characteristic. SOLUTION: Three elastic arms 10a, 10b, 10c separated by groove parts 11, 11 are formed in a vibrator 10. The arms are driven so that the both-side elastic arms 10b, 10c and the center elastic arm 10a are deformed reversely. An angular velocity is determined by detecting a vibration component in the orthogonal direction with the driving direction of the elastic arms in a rotation system. The vibrator 10 having the three elastic arms 10a, 10b, 10c can acquire stable vibration, even when being held so that the both faces thereof are sandwiched on prolonged lines from the groove parts 11, 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration type gyroscope which detects a rotational angular velocity by utilizing a Coriolis force generated when a vibrator rotates while vibrating, and in particular, adjusting a vibration frequency of the vibrator. The present invention relates to a vibrating gyroscope that can be easily and stably supported, and that has a structure that is highly productive.

[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 as a screen shake preventing device for video cameras.

As a gyroscope suitable for use in such various fields, a small one is required,
Therefore, a vibrating gyroscope is receiving attention.

FIG. 28 shows the basic structure of this type of vibrating gyroscope. In this vibrating gyroscope, a piezoelectric element 2 for driving and a piezoelectric element 3 for detection are attached to a columnar vibrator 1 formed of a constant elastic metal (elinvar). When the vibrator 1 is rotated about the axis O while the vibrator 1 is applied with bending vibration in the x-axis direction by the driving piezoelectric element 2, a Coriolis force acts on the vibrator 1 in the y-axis direction. The bending vibration of the vibrator 1 in the y-axis direction due to this Coriolis force is detected as a voltage by the piezoelectric element 3.

The mass of the vibrator 1 is m, and the piezoelectric element 2 for driving
The vibration velocity of the vibrator 1 in the x-axis direction given by
(Vector value) and the angular velocity about the O axis is ω (Vector value), Coriolis force F (Vector value) is

[0006]

[Equation 1] And the Coriolis force F is proportional to the angular velocity ω. The deformation vibration of the vibrator 1 in the y-axis direction due to the 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.

However, in the gyroscope shown in FIG. 28, an expensive constant elasticity metal is processed into a columnar shape, so that the material remains unsatisfactory and the columnar shape must be processed with high precision. High cost. In addition, in this type of gyroscope, it is necessary to adjust the resonance frequency when the vibrator 1 is flexurally vibrated by the driving piezoelectric element 2. For this reason, any part of the columnar vibrator 1 must be removed. It needs to be adjusted, and the adjustment work is very complicated.

Therefore, the inventor of the present invention has studied a bipod tuning fork type vibration gyroscope using a vibrator 4 made of a plate-shaped constant elastic metal as shown in FIG. This gyroscope has a groove 4a at the center of the tip of the vibrator 4.
And the inside of the flat plate is separated into two pieces of elastic arms 4b and 4c. As shown in FIG. 30 (A), the elastic arms 4b and 4c are vibrated at a natural resonance frequency along the plane direction of the plate using a driving piezoelectric element. This vibration is such that the amplitudes at a certain time point are in opposite phases as indicated by the + x direction and the −x direction by the elastic arms 4b and 4c. When the oscillator 4 is rotated about the axis O in the state where such vibration is applied, the elastic arms 4b and 4c are moved as shown in FIG.
As shown in (B), deformation in the + y and −y directions due to the Coriolis force occurs. The angular velocity ω can be obtained by detecting this deformation with a piezoelectric element for detection and converting it into a voltage.

[0009]

However, the vibrating gyroscope using the plate-shaped bipod tuning fork type vibrator 4 shown in FIGS. 29 and 30 has the following problems.

(1) In the two-leg tuning fork type, when adjusting the resonance frequency during driving, it is necessary to trim all the elastic arms 4b and 4c separately, so that the resonance frequency adjusting operation is complicated. Further, the elastic arms 4b and 4c may have an asymmetrical shape at the time of this adjustment. However, if the elastic arms 4b and 4c have an asymmetrical shape, the vibrator 4 may be twisted or a vibration node may appear at an asymmetrical position. The deformation due to the Coriolis force shown in 30 (B) cannot be detected with good balance and high accuracy.

(2) In the two-leg tuning fork type, when a deformation vibration in the y direction is generated in each elastic arm 4b, 4c due to the Coriolis force, the nodal lines of the vibration are shown by (a) and (b) in FIG. Appear in position. Therefore, the vibrator 4 needs to be supported in a cantilever manner at the center of the rear end of the vibrator 4, for example, and the supporting structure thereof is limited. With cantilevered support using the support rod 5, the mechanical support strength is unstable, and the vibrator 4 is easily affected by external vibration.

The present invention is intended to solve the above-mentioned conventional problems, and an object thereof is to enable a vibrator to be supported in a stable state in a vibration type gyroscope.

[0013]

According to the present invention, a vibrator having three elastic arms separated by two grooves, a driving means for generating vibration in at least one elastic arm, and a vibrator are provided. And a detection unit that detects a vibration component generated in the elastic arm in a direction intersecting with the vibration direction when rotated, and the elastic arms on both sides and the central elastic arm are deformed in opposite directions by the driving unit. And is vibrated, and is supported on at least the base portion on the extension line of each groove on both sides facing in the penetrating direction of the groove.

Further, preferably, when the depth dimension of the groove is L3 and the length in the same direction as L3 in the range where the groove is not formed and is not supported is L0, L0 / L3
Is 0.6 or more, and more preferably, when the depth dimension of the groove is L3, and the length in the same direction as L3 in the range where the groove is not formed and is not supported is L0,
L0 / L3 is 0.8 or more and 1.0 or less.

In the above means, two grooves are formed in the vibrator and three elastic arms are provided. For example, the vibrator is made of a constant elastic metal, and the driving means for applying vibration to the elastic arm and the detecting means for detecting the vibration are composed of a piezoelectric element bonded to the constant elastic metal. When at least one elastic arm is vibrated by the driving means, and the vibrator is rotated while the elastic arm is resonantly vibrating at a predetermined frequency, the Coriolis force causes the elastic arm to cross the vibration direction. Resonantly vibrates in the direction of. This vibration is detected by the detection means, and the rotational angular velocity is obtained from this detection output.

Further, the vibrator itself is made of a piezoelectric material, and AC power is applied to the driving electrode joined to the elastic arm, so that the elastic arm resonates and vibrates at a predetermined frequency. The resonance vibration generated in the elastic arm by Coriolis force is
It is detected as AC power by the detection electrode joined to the elastic arm, and thereby the rotational angular velocity is detected.

As described above, when the vibrator is provided with three elastic arms, it is not always necessary to trim all the elastic arms when adjusting the frequency of the resonance vibration of the elastic arms.

When a vibration mode in which the elastic arms on both sides and the central elastic arm are deformed in mutually opposite phases is adopted,
The resonance frequency can be adjusted simply by changing the length of the central elastic arm. This vibration mode is a vibration mode generated by driving the elastic arms on both sides and the central elastic arm in opposite phases. Or, if both elastic arms are driven together in the same direction and the central elastic arm vibrates in opposite phase due to the reaction force, or only the central elastic arm is driven and both elastic arms are driven by the reaction force. This is the case when vibration occurs in the opposite phase.

Further, when the elastic arms on both sides and the central elastic arm vibrate in mutually opposite phases, the amplitude of the base end where the groove of the vibrator is not formed becomes extremely small. It becomes possible to rigidly support. For example, by sandwiching at least the extended line portion of the groove at the base end with a rigid body, the vibrator can be supported with high strength. Since the base end of the vibrator can be rigidly supported, it becomes possible to stabilize the support of the vibrator.

When the oscillator is rigidly supported, the depth dimension of the groove is L3, and the length in the same direction as L3 in the range where the groove is not formed and is not rigidly supported is L0. , L0 / L3 is preferably 0.6 or more, and more preferably L0 / L3 is 0.8 or more and 1.0 or less. By selecting a dimension within this range, the electromechanical coupling coefficient (kvn) of the vibrator can be improved.
By selecting L0 / L3 in this range, the width dimensions of the elastic arms of the flat plate-shaped vibrator are the same, and the resonance vibration of the elastic arms in the y direction is higher than the resonance vibration in the x direction. In some cases, it is possible to improve and stabilize the electromechanical coupling coefficient, especially in resonance vibrations in the x direction.

Here, the electromechanical coupling coefficient represents the performance of electromechanical conversion, and is given by the square root of the ratio of the electrical energy applied to the oscillator in the dynamic state and the mechanical output energy resulting therefrom.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 10 is a perspective view of a vibrating gyroscope according to the first embodiment of the present invention, FIG. 11 is a plan view of its vibrator, and FIG. 12 is an end face of the vibrator showing its driving means, detecting means and circuit configuration. FIG. 13 (A) is a plan view showing another structure of the vibrator of the first embodiment, FIG. 13 (B) is a side view thereof, and FIG. 14 is a driving means and a detecting means in the structure shown in FIG. FIG. 15 is an end view of the vibrator showing the circuit configuration, and FIG.
16 is a diagram showing drive and detection characteristics in the structure shown in FIG.
19 is a diagram showing the characteristics of the electromechanical coupling coefficient in the structure shown in FIG. 13, and FIG. 20 is a perspective view showing the structure of the vibrator when the structure shown in FIG. 13 is further simplified. 21 is a perspective view of the vibrating gyroscope according to the second embodiment, FIG. 22 (A) is a plan view of the vibrator, and FIG. 22 (B) is an end view of the vibrator for showing the driving means and the detecting means. 24 is a perspective view of a vibrating gyroscope according to a third embodiment of the present invention, FIG. 25 is a perspective view showing a vibrator of a vibrating gyroscope according to a fourth embodiment of the present invention from the front and back sides, and FIG. FIG. 27 is an end view showing a circuit configuration for driving the child and detecting vibration, and FIG. 27 is a perspective view showing a vibration state of the vibrator of the fourth embodiment.

Further, FIGS. 1 to 9 and 23 explain the basic structure and function of the vibrator constituting the vibration type gyroscope, and also explain that each of the above-described embodiments is optimal. belongs to.

The inventor of the present invention has shown in FIG. 1 (A) (plan view)
And (B) (side view), it was studied to construct a vibrating gyroscope using the flat tripod tuning fork type vibrator 10.

The vibrator 10 is made of a constant elastic metal (elinvar) in a flat plate shape. This constant elasticity metal (elinvar) is a material whose Young's modulus hardly changes with room temperature near room temperature, and is, for example, an alloy of Ni (nickel), Cr (chromium) and Mn (manganese),
Or Co (cobalt), Fe (iron) and Cr (chrome)
And an alloy obtained by adding Ni (nickel) thereto.

In each of the following embodiments, the plate thickness direction of the plate-shaped vibrator is represented by y, and the direction orthogonal to the plate thickness direction y and along the plane of the plate is represented by x. Further, as shown in FIG. 2, the rotational angular velocity of the vibrator on the xy plane is represented by ω.

As shown in FIG. 1, the vibrator 10 has two grooves 11 and 11 of the same length cut from one end of a plate member of a constant elastic metal. The grooves 11 and 11 are in the plate thickness direction (y
Direction), so that the central elastic arm 10a and the elastic arms 10b, 1 on both the left and right sides thereof are formed.
0c and 0c are formed separately in the x direction. In FIG. 1, the total length of the vibrator 10 is L, the length of the central elastic arm 10a is L1, the total length of the base portion 10d in which the groove is not formed is L2,
The depth of both grooves 11, 11 is indicated by L3.

Each elastic arm 10a, 10b, 10c
Alternatively, when one elastic arm or two elastic arms are resonantly vibrated at a predetermined frequency in the plate surface direction (x direction) and the vibrator 10 is rotated, the elastic arms 10a, 10
b and 10c are deformed in the plate thickness direction (y direction) by the Coriolis force and resonate and vibrate. Since the Coriolis force is proportional to the angular velocity (ω) as described in Equation 1, y of each elastic arm
The angular velocity (ω) can be detected by converting the amount of deformation due to the vibration in the direction into a voltage using, for example, a piezoelectric element.

The vibration mode (amplitude phase) when each elastic arm deforms and vibrates in the y direction by the Coriolis force is the mode shown in FIG. 2 (hereinafter referred to as A mode) and the mode shown in FIG. (Hereinafter, referred to as B mode).

In the A mode shown in FIG. 2, the elastic arms 10 on both sides are arranged.
In this case, the amplitude directions of both b and 10c are + x direction at a certain point, and the central elastic arm 10a is driven together so that the amplitude direction is −x direction. At this time, when the oscillator 10 is rotated about the O axis at an angular velocity ω,
Coriolis force is generated, and the elastic arms 10b and 10c are deformed and vibrated so that both the amplitude directions are the + y direction and the central elastic arm 10a has the opposite amplitude direction. In FIG. 2, the elastic arms 10b and 10c on both sides and the central elastic arm 10a are oscillated in the ± x directions so that they have opposite vibration phases, but the same applies when the following drive is performed. It becomes A mode vibration.

First, without driving the central elastic arm 10a, the elastic arms 10b and 10c on both sides are both oscillated and driven so that the amplitude direction at a certain time point is the + x direction. At this time, the central elastic arm 10a is moved by the reaction force of the vibration of the elastic arms 10b and 10c in the + x direction.
And oscillate in the -x direction in the opposite phase to 10c. At this time, when the vibrator 10 is rotated about the O axis at an angular velocity ω, a Coriolis force is generated and the elastic arms 10b and 10c both vibrate in the + y direction at a certain point, and at this time, the amplitude of the central elastic arm 10a is increased. Vibration occurs in which the direction is opposite to the -y direction. Even in such a case, the A mode is set.

In the B mode shown in FIG. 4, the central elastic arm 10 is used.
The elastic arms 10b on both left and right sides are set to a neutral state without driving a.
And 10c are vibrated in opposite phases. That is, the amplitude direction due to the driving at a certain time point is the + x direction in one elastic arm 10b and the −x direction in the other elastic arm 10c. At this time, due to the Coriolis force, the amplitude direction of the elastic arm 10b becomes + at the same time point.
The elastic arm 10c is deformed and vibrated in the y direction so that the amplitude direction of the elastic arm 10c is the −y direction. The central elastic arm 10a is in a neutral state and does not vibrate in the y direction.

In the above A mode and B mode, when the elastic arm of the vibrator is driven in the x direction to cause resonant vibration, and the vibrator is rotated, the Coriolis force causes the elastic arm to generate resonant vibration in the y direction. Therefore, the angular velocity can be obtained by detecting the vibration in the y direction. Alternatively, conversely, the elastic arm of the vibrator is driven in the y direction to resonate, the vibrator is rotated, and the Coriolis force causes the elastic arm to vibrate in the x direction. The angular velocity can be detected by detecting this vibration.

Here, the adjustment of the frequency of the resonance vibration of each elastic arm in the y direction in each of the A mode and the B mode will be examined. FIG. 6 shows changes in the resonance frequency in the unsupported state in the A mode and the B mode when only the length dimension L1 of the central elastic arm 10a is changed. In the B mode, since the central elastic arm 10a is not vibrating, the length L1 of the elastic arm 10a is irrelevant to the resonance frequency.
It can be seen that the resonance frequency changes proportionally if only the length L1 of a is changed. That is, in the A mode shown in FIG. 2, the length of the central elastic arm 10a is cut by cutting the distal end thereof.
The resonance frequency can be freely adjusted only by changing 1. When L1 is lengthened, the resonance frequency is low, and when L1 is shortened by cutting the tip of the elastic arm 10a at the center, the resonance frequency becomes high.

FIG. 7 shows the base portion 1 in which the groove 11 is not formed.
The relationship between the length L2 of 0d and the frequency of the resonance vibration in the y direction is shown. In the A mode shown in FIG. 2, the length of the base portion 10d is irrelevant to the change in the resonance frequency.
In the B mode shown in, the resonance frequency changes proportionally when the length L2 of the base portion 10d is changed. Explaining the B mode, as shown in FIG. 4, in the B mode, the nodal lines when vibrating in the y direction are at the positions indicated by (a) and (b).
Here, when the dimension L2 of the base portion 10d shown in FIG. 5 (A) is long and the dimension L2 shown in FIG. 5 (B) is short,
The nodal line (b) moves toward the tip (to the right in the drawing) as the dimension L2 of the base 10d becomes shorter. When the nodal line (b) moves toward the distal end, the size of the substantially vibrating portion of the elastic arms 10b and 10c becomes shorter and the resonance frequency becomes higher. That is, in the B mode, the vibrator 10 is cut from the rear end or the depths of the grooves 11 and 11 are changed, and the dimension L of the base portion 10d is changed.
The resonance frequency can be adjusted simply by changing 2.

As described above, in order to adjust the resonance frequency of the vibration whose amplitude is in the y direction, in the A mode shown in FIG. 2, it is sufficient to cut the tip of the central elastic arm 10a, and as shown in FIG. In the B mode, it is only necessary to cut the base end of the vibrator 10, so the adjustment work is very simple. Further, since the symmetry of the shape of the vibrator 10 is not changed by these operations, the adjustment operation does not cause asymmetry to cause torsional vibration.

Further, regarding the adjustment of the resonance frequency in the above-mentioned resonance vibration in the y direction, the elastic arms 10a, 1 are adjusted.
There is no influence on the frequency of the resonant vibration of 0b and 10c in the x direction. Therefore, the frequencies of the resonance vibration in the y direction and the resonance vibration in the x direction of the elastic arms 10a, 10b, 10c can be made close to each other.

Next, the conditions for supporting the vibrator 10 will be examined. In the A mode shown in FIG. 2, when focusing on the vibration in the y direction, the central elastic arm 10a and the elastic arms 10b, 1 on both sides are arranged.
0c vibrates in opposite phases to each other, so that the grooves 11, 11
Amplitude + Δ at the base end of the base portion 10d in which no ridge is formed
y and −Δy are extremely small values (see FIG. 3). For example, when the depth L3 of the grooves 11 and 11 is 40 mm and the dimension L2 of the base portion 10d is in the range of 10 mm to 30 mm, the ratio between the amplitude y of the tip of the elastic arm and the amplitude Δy of the base end of the base portion 10d is , ± 1.0 to ± 1.0
It is about -3 (minus cube).

Therefore, in the case of the A mode in which the elastic arms 10b and 10c on both sides and the central elastic arm 10a are vibrated in opposite phases, what is the length L2 of the base 10d with respect to the depth L3 of the grooves 11 and 11? Even if the dimensions are different, when the base 10d is sandwiched and supported by a rigid body, the elastic arms 10a, 1
There is no great influence on the vibration modes of 0b and 10c. Therefore, as shown in FIG.
It is possible to provide a support structure in which the base end portion of the is clamped by the rigid bodies 12a and 12b. However, when it is rigidly supported, the base 1
The length dimension L0 of the portion of 0d which is not rigidly supported (see FIG.
3) affects the electromechanical coupling coefficient and resonance sharpness (Q value) of resonance vibration of the vibrator in the x direction. This point will be described in a later embodiment based on FIGS. 16 to 19.

Further, it is not always necessary to sandwich the entire width of the base portion 10d between the rigid bodies 12a and 12b. In the A mode of FIG. 2, since the nodal line (a) of the vibration is on the extension line of the grooves 11 and 11, even if the base portion 10d is sandwiched by the rigid bodies at the two positions of the extension lines of the grooves 11 and 11, the vibrator 10 is not required. The rigidity can be maintained in a sufficiently stable state.

Next, in the B mode shown in FIG. 4, as shown in FIGS. 4 and 5A and 5B, the node lines (a) and (b) are relative to the center line of the vibrator. The symmetrical shape,
The entire base portion 10d cannot always be rigidly supported as shown in FIG. In this case, as shown in FIG. 21, a structure in which the base portion 10d of the base portion 10d is supported by the support rod 13 is preferable.

However, the length La and the diameter Da of the support rod 13 affect the change of the resonance frequency of the vibration of the elastic arm in the y direction. In FIG. 23, (a) is the diameter Da
Shows the relationship between the length La of the support rod 13 of 0.5 mm and 0.8 mm and the resonance frequency of the vibrator. According to this diagram, as the dimension La of the support rod 13 becomes longer, this change in La does not affect the resonance frequency of the oscillator, and as the diameter Da of the support rod 13 becomes smaller, the change in Da becomes smaller. It does not affect the resonance frequency. Therefore, it is necessary to lengthen the support bar 13 to some extent, and for example, 15 mm or more is preferable. Further, the diameter Da of the support rod 13 needs to be reduced to some extent, and is preferably 0.5 mm or less, for example.

However, in the structure in which only one end of the vibrator 10 is supported by the support bar 13 as shown in FIG. 21, the mechanical support strength is weak and each elastic arm of the vibrator is easily affected by external vibration. . Therefore, as shown in FIG. 24, if the structure is such that the center of each end of the base portion 10d of the vibrator 10 and the central elastic arm 10a is supported from both sides by the support rods 13 and 14, the mechanical strength is remarkably increased. Can be improved. Even in this case, the length and diameter of each of the support rods 13 and 14 affect the resonance frequency, so it is necessary to set these dimensions to the optimum ones.

However, even in the B mode shown in FIG.
When the depth dimension L3 of the grooves 11 and 11 is 1/3 or less of the total length L, the amplitude of the base end of the base portion 10d is extremely small and becomes almost zero. Therefore, if the depth L3 of the groove is 1/3 or less of the total length L, even in the B mode, a support structure held by the rigid bodies 12a and 12b is possible as in the case shown in FIG.

Next, in the vibration type gyroscope,
The detection accuracy when detecting the vibration of the elastic arm in the y direction is related to the resonance sharpness (Q value) of the vibration of the elastic arm in the y direction.
Therefore, in the A mode and the B mode, the resonance sharpness when each elastic arm vibrates in the y direction will be examined.

First, in the A mode shown in FIG. 2, the relationship between the width dimension D1 of the central elastic arm 10a and the width dimension D2 of each of the elastic arms 10b and 10c on both sides greatly affects the resonance sharpness. This is because the mass or the moment of inertia of the elastic arm 10a and the elastic arm 10a which vibrate in the y direction in opposite phases to each other.
This means that the difference in mass or moment of inertia between b and 10c is closely related to the resonance sharpness.

Therefore, an oscillator having the same width dimension as D1 and D2 and an oscillator having D1 twice the width dimension of D2 are prepared.
The resonance sharpness (Q value) was measured by vibrating the elastic arm of each oscillator in the y direction in the A mode. As a result, D1
It was found that the sharpness (Q value) of the vibrator having a doubled D2 is almost doubled as compared with the vibrator having the same D1 and D2. That is, in the A mode shown in FIG. 2, the width dimension D1 of the central elastic arm 10a is set to the elastic arms 10b and 10c on both sides.
It is preferable that the width dimension D2 is approximately doubled.

However, in the A mode, when the width dimension of the central elastic arm 10a and the width dimensions of the elastic arms 10b and 10c on both sides are the same dimension D (see FIG. 13), the resonance frequency in the x direction and the y direction It is possible to approach the resonance frequency to. That is, when the width dimension of the central elastic arm 10a and the elastic arms 10b and 10c on both sides are the same D, and each elastic arm is vibrated in the primary resonance mode in the x direction and in the secondary resonance mode in the y direction. , And the frequencies in both resonance modes in the x direction and the y direction can be made close to each other, which is preferable as a vibration type gyroscope.

In this case, the length dimension L0 of the portion where the groove 11 of the vibrator 10 is not formed and the portion which is not rigidly supported and the depth dimension L3 of the groove 11 are within a certain range ratio. When set, the electromechanical coupling coefficient and resonance sharpness (Q value) of resonance vibration of the vibrator in the x direction are improved or stabilized. FIG. 13 shows a preferred embodiment using the vibrator in this case, and FIGS. 16 to 19 explain the relationship between the above-mentioned dimensional ratio and the electromechanical coupling coefficient. .

Next, in the case of the B mode shown in FIG. 4, the resonance sharpness (Q value) when the elastic arm of the vibrator vibrates in the y direction is as shown in FIG. It is affected by the length La and the diameter Da of the support rod 13. FIG. 23B shows the relationship between the length La of the support rod 13 and the Q value when the diameter Da of the support rod 13 is 0.5 mm and 0.8 mm. According to FIG. 23B, the length La of the support rod 13 is, for example, 15 mm or more, and the diameter Da is, for example, 0.
By setting the thickness to 5 mm or less, deterioration of sharpness (Q value) can be suppressed. This also applies to the case where the support rods 13 and 14 are supported from both ends as shown in FIG.

Next, the primary or secondary vibration mode of each elastic arm will be described. FIG. 8 shows x of each elastic arm 10a, 10b, 10c at a certain point in the A mode.
The deformed state in the direction is shown by a dotted line, and FIGS. 9A and 9B show the deformed state when each elastic arm vibrates in the y direction.

The elastic arms 10a, 10b, 10c are respectively driven in the x direction by driving means such as piezoelectric elements. At this time, as shown in FIG. 8, they resonate in the primary vibration mode. The elastic arm that vibrates in the y direction due to the Coriolis force resonates in the secondary vibration mode shown in FIG. 9 (A), the tertiary vibration mode shown in FIG. 9 (B), or higher vibration modes higher than that. Will be done. In addition, elastic arms 10a, 10b,
The same applies when 0c is oscillated in the y direction and the elastic arm vibrates in the x direction due to the Coriolis force.

The fact that the resonance in the y-direction is higher than the resonance in the x-direction is one of the characteristics of using the flat plate-shaped vibrator. By using a plate-shaped vibrator, the material remains well, and trimming during adjustment is easy, and the vibrator can be mass-produced at low cost. Further, by setting the width dimension of the elastic arm, it is possible to bring the frequency of resonance vibration of a predetermined order in the y direction close to the frequency of resonance vibration in the x direction, which is a resonance mode of a lower order than this. is there.

Further, the elastic arm is vibrated in the x-direction in the secondary or higher resonance mode, and the third-order or the fourth-order in the y-direction.
It is the same even when vibrating in the following resonance vibration modes.

In the flat-plate vibrator, similarly, in the B mode, the resonance vibration in the y direction is higher than the resonance vibration in the x direction.

FIGS. 10 to 12 show a first embodiment of the vibration type gyroscope in which the vibration mode is the A mode shown in FIG. 2 based on the above examination result.

As shown in FIGS. 11 and 12, the central elastic arm 10a is provided with two pairs of driving piezoelectric elements 26 as driving means on both front and back surfaces thereof, and the elastic arms 10b and 10c on both sides are provided.
Similarly, driving piezoelectric elements 27, 2 are also used as driving means.
8 are attached one by one from both front and back sides. The polarization direction of each piezoelectric element is indicated by (+) in the right direction in the drawing and by (-) in the left direction in the drawing in FIG. Electrodes are provided on the front and back surfaces of each of the piezoelectric elements 26, 27, 28, and one of the electrodes has each of the elastic arms 10a, 10b,
The surface of 10c is in close contact with the surface of the element 10c for electrical continuity, and is grounded via the vibrator 10. Then, as shown in FIG. 12, electric power is applied to the electrodes on the surfaces of the respective piezoelectric elements 26, 27, 28 from a driving AC power source.

As a result of setting the polarization directions of the driving piezoelectric elements 26, 27, 28 as shown in FIG. 12, as shown in FIG. 2, the central elastic arm 10a and the left and right elastic arms 10b,
It vibrates so as to have a phase opposite to that of 10c (amplitude at a certain point is ± reverse of the x direction).

A pair of front and back piezoelectric elements 21 for detection are attached to the central elastic arm 10a as detection means, and a pair of front and back piezoelectric elements for detection are also attached to the left and right elastic arms 10b and 10c respectively. 22 and 23 are attached. The polarization directions of these piezoelectric elements 21, 22, and 23 are also as shown by (+) (-) in FIG. One electrode of each piezoelectric element 21, 22, 23 is an elastic arm 1
Grounded in close contact with the surfaces of 0a, 10b, and 10c, and the output from the electrodes on the surface side is collected to obtain the detection voltage V.

The elastic arms 10a, 10b, 10c are oscillated and driven, for example, in the primary resonance mode so that the amplitude directions at a certain time point are the + x direction and the -x direction, and the vibrator 10 in this state is rotated. Then, Coriolis force acts on each elastic arm. This Coriolis force is applied to each elastic arm 10a,
Vibration velocity v (vector value) of 10b and 10c in the x direction
And each elastic arm vibrates in the y direction in, for example, the secondary resonance mode.

When the elastic arms 10a, 10b, 10c vibrate in the y direction due to the Coriolis force, the surface distortion of the elastic arms is converted into a voltage by the piezoelectric elements 21, 22, 23 for detection, and is converted into AC power. Is output. In the gyroscope, the angular velocity ω is calculated based on the sum of the AC power detected by the piezoelectric elements 21, 22, 23 for detection described above.

According to the above examination, in the A mode, the groove 1
Since the amplitude of the base portion 10d in which 1 and 11 are not formed is very small, the nodal line (a) of the vibration or the base portion 10d
The entire width direction of d can be sandwiched by the rigid bodies 12a and 12b, and the mechanical support is very stable.

In order to improve the resonance sharpness (Q value), the width dimension D1 of the central elastic arm 10a is set to the left and right elastic arms 1.
It is preferable to double the width dimension D2 of 0b and 10c.

Further, as shown in FIG. 6, in the A mode, the resonance frequency can be adjusted by changing the length L1 of the central elastic arm 10a. Therefore, the frequency adjustment work only needs to trim the tip of the central elastic arm 10a.

13 and 14 show another structure of the vibrator in the first embodiment, FIG. 13 (A) is a plan view of the vibrator, FIG. 13 (B) is a side view of the vibrator, and FIG. 14 is an end view of the vibrator.

The vibrator 10 is made of a flat elastic metal (elinvar) having a thickness t0, and elastic arms 10a, 10b, 1 separated by the grooves 11, 11.
The width of 0c has the same dimension D. The depth dimension of the groove 11 is L3, and in the base portion 10d where the groove 11 is not formed, the length dimension of the portion not supported by the rigid bodies 12a and 12b in the same direction as the L3 is L0.

The vibration of the vibrator 10 is in the A mode as in the embodiment of FIG. As shown in FIG. 14, each elastic arm 10a, 10b, 10c is provided with a piezoelectric element 26, 27, 28 as a drive means, and each elastic arm 10a, 10b, 10c is provided with a piezoelectric element as a detection means. Elements 21, 22, 23 are provided. The polarization directions (+) and (-) of each piezoelectric element are as shown by arrows in FIG.

By the above piezoelectric elements 26, 27 and 28,
The elastic arm of the vibrator 10 is driven in the x direction shown in FIG. 2 and vibrates at the primary resonance. When the vibrator 10 rotates about the center line O as shown in FIG. 2, each elastic arm 10a, 10b, 10
In c, a secondary resonance vibration due to the A mode in the y direction occurs due to the Coriolis force. This vibration is detected by the piezoelectric elements 21, 22, and 23 as a detection means, and a detection output is obtained.

In FIG. 13, the thickness dimension of each piezoelectric element is t1.
, And the length and width dimensions of the piezoelectric element are Ls.
And d.

Table 1 below shows the dimensions D,
A specific combination of L3, t0 and the dimensions Ls, d, t1 of each piezoelectric element is shown. I to IV are sample numbers of the vibrators of the respective sizes.

[0072]

[Table 1]

FIG. 15 shows the detection accuracy of the angular velocity ω when the length dimension L0 of the portion of the base portion 10d that is not rigidly supported is 180 mm in the vibrator of the sample III whose dimensions are shown in Table 1 above. Is shown.

An AC voltage having a peak-to-peak value of 5 V is applied to each of the driving piezoelectric elements 26, 27, 28 at a driving frequency of 8116 Hz, so that each elastic arm 10a, 10b ,.
10c was driven in the x direction and vibrated at the primary resonance. By setting the elastic arms 10a, 10b, and 10c to have the same width dimension D, the value of the primary resonance vibration in the x direction and the frequency of the secondary resonance vibration in the y direction are close to each other at the resonance of the A mode. become. The drive frequency 8116 Hz is set for each elastic arm 1.
0a, 10b, 10c primary resonance frequencies in the x direction,
The frequency is set to an intermediate frequency between the secondary resonance frequencies in the y direction.

This vibrator 10 is rotated by changing the angular velocity ω with respect to the center line O in the xy plane, and each elastic arm is vibrated by the secondary resonance in the y direction. At this time, the piezoelectric element for detection is used. The outputs obtained from 21, 22, 23 were measured. Figure 15
Indicates the angular velocity ω (deg / sec) on the horizontal axis and the detection output (Vout / Vin) from the piezoelectric element on the vertical axis. However, the output Vout is shown as an effective value. In FIG.
When the vibrator of the sample III is rotated, the detection output at a predetermined angular velocity is measured 5 times each, and the average value thereof is taken and shown in the diagram. As shown in FIG. 15, the detection output changes linearly in proportion to the angular velocity. Therefore, it is understood that the angular velocity can be proportionally calculated from the detected output.

Next, in the vibrator having the structure shown in FIG. 13 and FIG. 14, the ratio of the length dimension L0 of the portion of the base portion 10d which is not rigidly supported to the depth dimension 13 of the groove 11 is the electric potential of the transducer. -The effect on the mechanical coupling coefficient was investigated.

FIGS. 16 to 19 show L0 for samples I, II, III and IV having the dimensions shown in Table 1, respectively.
The electric / mechanical coupling coefficient when the ratio of / L3 is changed from 0.1 to 1.0 is shown. In each figure, the line connecting the white circles is the electric force of the primary resonance vibration of each elastic arm in the x direction.
The mechanical coupling coefficient (kvn) is shown, and the line connecting the black circles shows the electromechanical coupling coefficient (kvn) at the secondary resonance vibration of each elastic arm in the y direction.

In each of the figures, the primary resonance vibration in the x direction indicated by a white circle has a lower conversion efficiency between the electrical system and the mechanical system than the secondary resonance vibration in the y direction, and x It can be seen that in the first-order resonance vibration in the direction, the ratio of L0 / L3 greatly affects the efficiency of conversion between the electric system and the mechanical system. In each of the samples I to IV, L0 / L3 is preferably 0.6 or more so that the electromechanical coupling coefficient in the primary resonance vibration in the x direction becomes a stable value to some extent. More preferably, L0 / L3 is 0.8 or more.
That is, the depth dimension L3 of the groove 11 (elastic arms 10a, 10
b, 10c), the longer the dimension L0 of the portion of the base 10d that is not rigidly supported, the better the efficiency of conversion between the electrical system and the mechanical system in the primary resonance in the x direction, and The sharpness (Q value) can be improved and stabilized. Further, in FIGS. 16 to 19, when L0 / L3 approaches 1, the electromechanical coupling coefficient further increases, but when L0 / L3 exceeds 1, the vibration balance of the entire vibrator may be disturbed. Therefore, the preferable range of L0 / L3 is 0.6 or more,
Similarly, the preferable range is 0.6 or more and 1.0 or less, and the more preferable range is 0.8 or more and 1.0 or less.

In the embodiment shown in FIG. 10 and the embodiment shown in FIG. 13, each elastic arm is driven by the second resonance vibration in the y direction by the piezoelectric element, and each elastic arm is driven by the Coriolis force when the vibrator rotates. It is possible to detect the primary resonance vibration in the x direction in the elastic arm by the piezoelectric element and detect the angular velocity from this output.

The second embodiment shown in FIGS. 21 and 22 is a vibration gyroscope configured so that the vibration mode of the vibrator 10 becomes the B mode shown in FIG.

As shown in FIG. 22, in the B mode, only the left and right elastic arms 10b and 10c vibrate. Therefore, the piezoelectric elements 36 and 37 as the driving means are attached to the both elastic arms 10b and 10c, one pair on the front and one on the back. Has been. Then, the piezoelectric element 31 as a detecting means is attached to each elastic arm 10b and 10c.
And 32 are mounted on the front and back respectively.

The polarization direction of each piezoelectric element is indicated by (+) in the right direction and by (-) in the left direction in FIG. 22B.
One electrode of each piezoelectric element has elastic arms 10b and 10b.
It is closely attached to the surface of c and grounded. Then, as in FIG. 12, AC power is applied to the electrodes on the surfaces of the driving piezoelectric elements 36 and 37, and the detection output is taken out from the electrodes on the surfaces of the detecting piezoelectric elements 31 and 32.

As shown in FIG. 4, in the B mode, the driving piezoelectric elements 36 and 37 drive the elastic arms 10b and 10c so that the amplitudes are in the + x direction and the -x direction at a certain point in time. Y of both elastic arms 10b and 10c caused by
The surface strain of the deformation vibration in the direction is detected by the piezoelectric elements 31 and 3
Converted to a voltage with 2. The angular velocity ω can be detected by taking the sum of this AC power.

When using this B-mode oscillator,
As shown in FIG. 21, it is general that the support bar 13 supports the center of the base end of the base portion 10d.
As shown in FIG. 4, mechanical support is stabilized by supporting the center of the base end of the base portion 10d and the center of the tip end of the elastic arm 10a by the support rods 13 and 14, respectively. In the case of the support structure shown in FIG. 21, the length La of the support bar 13 is, for example, 15 m.
By setting the diameter to m or more and the diameter Da to 0.5 mm or less, the resonance frequency can be stabilized and the Q value can be increased. Also in the case of both-ends support shown in FIG. 24, the resonance frequency can be stabilized and the Q value can be increased by selecting the length and diameter of each of the support rods 13 and 14.

Further, even in the B mode, the groove 11
If the depth dimension L3 of is less than 1/3 of the total length L, the base 1
Since the amplitude of the base end of 0d can be made almost 0, by setting the dimension of the groove 11 in this way, a structure in which the base 10d is held by the rigid bodies 12a and 12b is possible as in the case shown in FIG. is there.

In the B mode, since the resonance frequency can be changed by changing the dimension L2 of the base 10d as shown in FIG. 7, the base end of the base 10d is trimmed or the grooves 11 and 11 are formed. The adjustment work of the resonance frequency can be simplified by changing the depth of.

Also in this embodiment, the elastic arm 10b is also used.
And 10c are oscillated by driving them in the ± y directions so as to have opposite phases to each other, and vibrations in the ± x directions caused by the Coriolis force when the vibrator 10 is rotated are detected, and the angular velocity ω is obtained from this detection output. May be.

Next, FIGS. 25 to 27 show the fourth embodiment of the present invention.
The vibrator 40 of the vibration type gyroscope of the example is shown.

In this embodiment, the entire vibrator 40 is made of a piezoelectric material. And from the tip to the grooves 41, 41
Is cut, and three elastic arms 40a, 40b, 40c are cut.
Are formed. The polarization direction in each elastic arm 40a, 40b, 40c is as shown by the white arrow in FIG.

In this vibrator 40, the elastic arms 40 on both sides are
b and 40c are dedicated to driving, and the central elastic arm 40a is dedicated to detection.

As shown in FIG. 26, the elastic arm 40 for driving is used.
Driving electrodes 51a and 51b to 54a and 54b are laminated and provided on the surfaces of b and 40c. Among the driving electrodes, 51a, 52b, 53a, 54b are grounded, respectively, and AC power is applied to 51b, 52a, 53b, 54a. As a result, as shown in FIG. 27, the elastic arms 40b and 40c vibrate at the same time in the same amplitude direction as indicated by, for example, -x. When this oscillator is rotated about the axis O, Coriolis force acts on the elastic arms 40b and 40c, and the elastic arms 40b and 40c move in the same direction, for example, -y.
It deforms and vibrates in the direction.

When both elastic arms 40b and 40c vibrate in the same phase in the x direction, the reaction force causes the elastic arm 40a at the center to move.
Vibrates in a phase opposite to that of the elastic arms 40b and 40c. For example, in the case of the amplitude direction −x direction of the elastic arms 40b and 40c at a certain point, the amplitude direction of the central elastic arm 40a is the + x direction. That is, the elastic arms 40b, 40 driven in the x direction
The elastic arm 40a at the center with respect to c is deformed and vibrates in the opposite direction so as to maintain a mechanical balance. At this time, the central elastic arm 40a vibrates in the + y direction by the Coriolis force.

Therefore, as shown in FIG. 26, detection electrodes 61a to 63b are provided on the surface of the central elastic arm 40a. 61 of the electrodes for detection
b, 62a, 63b are grounded, 61a, 62b, 6
AC power is detected between 3a and ground.

The vibrating state in the y direction in the fourth embodiment is
This is the same A mode as shown in the embodiment of FIG.
Therefore, the base end of the oscillator 40 can be sandwiched and supported by a rigid body, and the resonance frequency can be changed by changing the length of the central elastic arm 40a.
The effect as A mode can be exhibited. Further, the preferable range of the ratio of the dimension L0 of the portion of the base portion 10d that is not rigidly supported and the groove depth L3 (length of the elastic arm) shown in FIG.
This is the same as described in the embodiment of FIG.

Further, in the embodiment of FIG. 25, when the elastic arms 40b and 40c on both sides are driven, the driving vibration direction is set to the y direction, and the reaction force causes the central elastic arm 40a to vibrate in the opposite direction to cause Coriolis. Vibration in the x direction caused by force may be detected by the detection electrodes.

In each of the above embodiments, the three elastic arms 10a, 10b, 10c or 40a, 40b, 40c are used.
Two or three of them are driven so as to cause resonant vibration in the x direction or the y direction, and the angular vibration ω is obtained by detecting the resonant vibration in the y direction or the x direction of each elastic arm caused by the Coriolis force. However, the three elastic arms 10a, 1
1 of 0b, 10c or 40a, 40b, 40c
Only one elastic arm may be driven. For example, only the central elastic arm 10a or 40a is driven so as to resonate in the x direction or the y direction, and the vibration of the central elastic arm 10a or 40a in the y direction or the x direction generated by the Coriolis force during rotation is detected. From this, the angular velocity ω may be obtained.
Also in this case, the resonance frequency is adjusted by the elastic arm 10 which is a plate material.
It is sufficient to trim only a or 40a, and the adjustment work is easy.

Also, in the embodiment of FIGS. 10 and 11, the embodiment of FIG. 13, and the embodiment of FIGS. 21 and 22, only one of the three or two elastic arms that resonate and vibrate by the Coriolis force is used. The vibration may be detected to obtain the angular velocity ω.

In each of the above embodiments, the vibrator has a thin plate shape such that when the vibration in the x direction is the primary resonance, the vibration in the y direction is the secondary resonance. May be, for example, a flat plate material having a certain thickness as shown in FIG. Alternatively, it may be a tripod tuning fork type vibrator in which each elastic arm has a square cross section.

Further, as shown in FIG. 20, flat plate-shaped bipod tuning fork type vibrators 10A and 10B are connected to a rigid spacer 10D.
Rigid joint with the elastic arm 10
Alternatively, the elastic arms 10b and 10c may be formed by forming a and forming plate members on both sides. This simple type tripod tuning fork type transducer
It can be used in place of the vibrator in each of the above-mentioned embodiments, and can be operated with each of A-mode and B-mode vibrations.

[0100]

As described above, according to the present invention, the vibrator is provided with three elastic arms. However, it is not always necessary to trim all the elastic arms when adjusting the resonance frequency. It is only necessary to change the length of the elastic arm, or the frequency can be easily adjusted by changing the length of the base portion where the groove is not formed. Further, as a result of the adjustment, there is almost no possibility that the vibrator will be asymmetrical.

Also, by adopting a structure in which the elastic arms on both sides and the central elastic arm vibrate in opposite phases, it becomes possible to support the base of the vibrator from both sides, and vibration of stable support can be achieved. Type gyroscope can be configured.

In the above, by setting the ratio of the length dimension of the portion where the groove is not formed and is not supported and the depth of the groove or the length of the elastic arm to the above preferable range, the electrical system and the mechanical system are It is possible to improve the efficiency of conversion to and from the system and improve or stabilize the resonance sharpness.

[Brief description of drawings]

1A is a plan view showing a structure of a vibrator, FIG. 1B is a side view thereof, FIG.

FIG. 2 is a perspective view of a vibrator showing an A mode in which adjacent elastic arms vibrate in opposite phases;

FIG. 3 is a schematic explanatory view for explaining the amplitude of the base portion of the vibrator in A-mode vibration,

FIG. 4 is a perspective view of a vibrator showing a B mode in which a central elastic arm does not vibrate;

5 (A) and 5 (B) are plan views of a transducer for explaining the change in the position of the nodal line when the length of the base is changed in the B mode.

FIG. 6 is a diagram showing a change in resonance frequency when the length of the central elastic arm is changed,

FIG. 7 is a diagram showing a change in resonance frequency when the length of the base is changed,

FIG. 8 is a schematic explanatory view showing a state in which the elastic arm is driven in the primary vibration mode in the x direction,

9A is a schematic explanatory view showing a state in which an elastic arm is driven in a secondary vibration mode in ay direction, and FIG. 9B is a schematic explanatory diagram showing a state in which the elastic arm is driven in a tertiary vibration mode;

FIG. 10 is a perspective view of a first embodiment which is a vibration type gyroscope for A mode vibration;

FIG. 11 is a plan view of the vibrator according to the first embodiment,

FIG. 12 is an end view of a vibrator showing a driving means, a detecting means, and a circuit configuration of the first embodiment,

13A and 13B show a vibrator having another structure according to the first embodiment, in which FIG. 13A is a plan view and FIG. 13B is a side view.

FIG. 14 is an end view of FIG. 13A showing a driving means, a detecting means, and a circuit configuration;

15 is a detection characteristic diagram of the vibration type gyroscope shown in FIG.

16 is a diagram showing characteristics of the electrical / mechanical coupling coefficient of Sample I shown in Table 1, FIG.

FIG. 17 is a diagram showing characteristics of the electrical / mechanical coupling coefficient of Sample II shown in Table 1.

FIG. 18 is a diagram showing characteristics of the electromechanical coupling coefficient of Sample III shown in Table 1.

FIG. 19 is a diagram showing the characteristics of the electromechanical coupling coefficient of Sample IV shown in Table 1,

FIG. 20 is a perspective view when the vibrator has a simple structure,

FIG. 21 is a perspective view of a vibrating gyroscope for B-mode vibration according to a second embodiment;

FIG. 22A is a plan view of the vibrator of the second embodiment,
(B) is its end view,

FIG. 23 is a diagram showing the relationship between the resonance frequency and the length and diameter of the support rod in B mode;

FIG. 24 is a perspective view showing a third embodiment which is a B-mode gyroscope in which the central portion of the vibrator is supported at both ends;

FIG. 25 is a perspective view showing the vibrator of the fourth embodiment formed of a piezoelectric material from both the front and back sides,

FIG. 26 is an end view of a vibrator showing the arrangement of drive electrodes and detection electrodes in the fourth embodiment;

FIG. 27 is a perspective view showing a deformed state of the vibrator of the fourth embodiment at a certain time point;

FIG. 28 is a perspective view showing a vibrator of a conventional vibrating gyroscope,

FIG. 29 is a perspective view showing a two-legged tuning fork type vibrator made of a plate material;

30A is a schematic diagram showing a driving vibration state of the vibrator of FIG. 29, FIG. 30B is a schematic diagram showing deformation by Coriolis force,

[Explanation of symbols]

10 oscillators, 10a, 10b, 10c elastic arm 10d base 11 grooves 12a, 12b rigid body 13,14 Support rod 21,22,23 A mode detection piezoelectric element 26, 27, 28 Piezoelectric element for driving in A mode Piezoelectric element for detection in 31, 32 B mode 36,37 Piezoelectric element for driving in B mode 40 oscillators 40a, 40b, 40c elastic arm 51a-54b Driving electrodes 61a-63b Detection electrodes

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazumasa Onishi             1-7 Aki, Otsuka-cho, Yukiya, Ota-ku, Tokyo             Su Electric Co., Ltd. (72) Inventor Akira Sato             1-7 Aki, Otsuka-cho, Yukiya, Ota-ku, Tokyo             Su Electric Co., Ltd. F term (reference) 2F105 AA01 AA06 AA08 BB04 CC04                       CD02 CD06 CD13

Claims (3)

[Claims] 1. A vibrator having three elastic arms separated by two grooves, drive means for generating vibration in at least one elastic arm, and generated in the elastic arm when the vibrator rotates. A detection means for detecting a vibration component in a direction intersecting with the vibration direction, wherein the driving means causes the elastic arms on both sides and the central elastic arm to deform and vibrate in mutually opposite directions. ,
A vibrating gyroscope, which is supported on at least a base portion on an extension line of each groove on both sides facing each other in a penetrating direction of the groove. 2. When L3 is the depth of the groove and L0 is the length in the same direction as the L3 in the range where the groove is not formed and is not supported, L0 / L3 is 0.6. The vibrating gyroscope according to claim 1, which is the above. 3. When the depth dimension of the groove is L3 and the length in the same direction as L3 in the range where the groove is not formed and is not supported is L0, L0 / L3 is 0.8. The vibrating gyroscope according to claim 1 or 2, which is 1.0 or less.