JPH11311519A - Rotating gyro - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rotating gyro which can be miniaturized, whose S/N ratio can be enhanced and whose detecting accuracy can be enhanced, by a method wherein a plurality of rotation parts are installed, the rotation parts are turned at an identical set speed in mutually opposite directions as viewed from a standstill system and the difference in a rotational speed between the plurality of rotation parts as viewed from a coordinate system is detected by the coordinate system which measures the rotational speed. SOLUTION: Rotation parts in a rotating gyro are a rotor MR1 and a rotor MR2 in a motor which is driven electromagnetically. For example, a current flows in the coil of a stator MS1 by a drive circuit MD1, a magnetic pole which is close to the rotor MR1 becomes an S-pole, a part which is magnetized to be an N-pole is attracted, and the rotor MR1 is turned around a shaft MJ1. The speed of rotation of the rotor MR1 is decided by the driving frequency |Ω| of the drive circuit MD1. The speed of rotation of the rotor MR1 and that of the rotor MR2 can be observed, from an encoder ME1, at -|Ω+ω| and |Ω-ω| (where Ω represents the frequency of the drive circuit MD1, and ω represents the speed of rotation of an enclosure MB. When the angular frequency of the output of the encoder ME1 is compared with the angular velocity of the output of an encoder ME2, the rotational speed can be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary gyro for detecting an angular velocity.

[0002]

2. Description of the Related Art Conventionally, mechanical rotary gyroscopes have been used as inertial navigation devices for airplanes and ships. It is difficult.

In recent years, however, research into miniaturization of gyroscopes has been advanced, and a vibrating body is excited by a piezoelectric element, and a voltage generated by vibration generated by Coriolis force applied to the vibrating body by rotation of another vibrating body provided on the vibrating body. The vibrating gyroscope for detecting the vibration has been put into practical use, and is used in a car navigation system, a camera shake detecting device of a video camera, and the like.

[0004] A prior art sound piece type vibration gyro using a piezoelectric element will be described below with reference to the drawings. For example, FIG.
Is the 2nd meeting of the Acoustical Society of Japan, September 1990, 2-Q-8.
Is a perspective view showing a conventional quadrangular vibrating gyroscope disclosed in US Pat.

A conventional vibrating gyroscope of the reed type will be described with reference to FIG. The vibrating body 71 has a sound piece type structure made of a constant elastic metal such as an elinvar. That is, the vibrating body 71 is a quadrangular prism and has a structure that supports the vicinity of a node of two primary vibration modes of the rod-shaped vibrating body that are orthogonal to each other. The drive unit and the drive electrodes 72 and 73 made of a piezoelectric element are bonded to two sides of a square pole. Drive electrodes 72 and 73
Serves also as a detection unit and a detection electrode. Here, the direction orthogonal to the side surface of the vibrating body 71 on which the drive electrode 72 is attached is the X-axis direction, the direction orthogonal to the side surface of the vibrating body 71 on which the drive electrode 73 is attached is the Z-axis direction, and the direction in which the column extends is Y. In the axial direction.

The operation will be described. The alternating voltage applied to the drive electrode 72 causes a bending vibration in the X direction to occur in the square pole. When the entire tuning fork is rotated around the Y axis at an angular velocity ω in a state where the bending vibration in the X direction occurs, a Coriolis force Fc acts in the Z direction orthogonal to the bending vibration in the X direction. The Coriolis force Fc can be expressed by the following equation. Fc = 2 · M · ω · V Here, M is an amount proportional to the mass of the vibrating part, and V is the speed of vibration. This Coriolis force Fc excites bending vibration in the X direction and bending vibration in the Z direction that is displaced in a direction perpendicular to the X direction. By detecting the AC voltage generated by the bending vibration in the Z direction with the detection electrode 73, the angular velocity ω can be calculated and known.

[0007]

However, the conventional vibrating gyroscope has the following problems. In general, when a vibrating body is reduced in size while maintaining similarity, the frequency increases and the drive amplitude decreases.However, the Coriolis force is generally inversely proportional to the frequency, and the detection voltage of the Coriolis force is proportional to the drive amplitude. The detection voltage becomes very small. Assuming that there is no difference in other conditions, the detection S / N decreases as the detection voltage decreases. As a result, the smaller the size of the vibrating gyroscope, the lower the accuracy of the angular velocity detecting device. For these reasons, the vibrating gyroscope has not been sufficiently reduced in size.

[0008] The object of the present invention is to solve the above-mentioned problems, and a small S / N ratio can be obtained even with a small size.
The present invention provides a rotary gyro that is large and has high detection accuracy.

[0009]

Means for Solving the Problems In order to solve the above-mentioned object, a rotary gyro according to the present invention employs the following configuration.

A rotary gyro according to the present invention includes two rotating portions that rotate at the same constant speed in opposite directions to each other when viewed from a stationary system. A rotation speed difference between the two rotation units.

[0011] Two rotating units are provided for performing rotation converging to the same constant speed within a certain time in opposite directions when viewed from the coordinate system for measuring the rotational speed. A rotating phase difference between the two rotating units.

The rotating part is a rotor made of a permanent magnet, the driving part is a stator made of an electromagnet, and the detecting part is an encoder made of an electromagnet.

The rotating portion is a center of gravity of each of the vibrating portions of the vibrating body supporting the nodes of the vibration, and is provided with a vibrating means for vibrating the vibrating body from two directions, and detects the vibration from one direction. It is characterized by comprising detecting means.

[0014] The vibrating body is a sound piece supporting a node of vibration.

The vibrating body is a four-leg tuning fork supporting a node of vibration.

The foot is made of an elastic material, the foot is a quadrangular prism, the foot has a driving unit and a detecting unit on the side surface of the quadrangular prism, the driving unit and the detecting unit are made of piezoelectric elements, and the base is It is made of an elastic material, the base is a quadrangular prism, the base and the four legs are of an integral structure, and the four legs are arranged in parallel with each other in a cross-shape on the base. Is used for support, causes the first and second feet to perform self-oscillation using the piezoelectric elements of the first and second feet, and causes the first and second feet to perform a first bending vibration in which the first and second feet swing in phase with each other. Self-oscillation is performed using the piezoelectric elements of the first and second feet, and the frequency of the first bending vibration matches the frequency in a direction orthogonal to the first bending vibration;
A second flexural vibration in which the phase is different by 90 degrees and the first leg and the second leg swing in the same phase is generated in advance, and the first flexural vibration and the second flexural vibration are combined as the first flexural vibration. The center of gravity of the cross section in the direction of extension of the foot of the foot and the center of gravity of the cross section in the direction of extension of the foot of the second foot generate a first rotational movement that is a rotational movement that rotates in opposite directions to each other. The movement causes the frequency change of the first bending vibration or the second bending vibration caused by the Coriolis force due to the rotation of the base to change the frequency of the first bending vibration or the second bending vibration in the same direction as the first foot and the second foot. The detection is performed by the detection unit of the fourth foot rotating in the direction.

A voltage output generated by the first flexural vibration having a changed phase on the piezoelectric element attached to the third foot and a first flexural vibration having a changed phase are attached to the fourth foot. An adder circuit for adding a voltage output generated by the piezoelectric element, a phase shift circuit for shifting the output of the adder circuit by 90 degrees, a binarizing circuit for binarizing the output of the phase shift circuit, A voltage output generated by the first flexural vibration having a changed phase on the piezoelectric element attached to the third leg, and a piezoelectric output having the first flexural vibration having a changed phase attached to the fourth leg. A subtraction circuit for subtracting a voltage output generated by the element is provided, and a lock-in amplifier for detecting an output of the subtraction circuit using an output of the binarization circuit is provided.

An amplitude / phase adjusting circuit for adjusting an output signal of the oscillation circuit so that the trajectory of the first rotational movement becomes a substantially circular trajectory is provided.

When viewed from the coordinate system for measuring the rotational speed, the rotating system includes a rotating unit for performing a rotation that converges to the same constant speed within a fixed time. A rotating gyroscope having means for detecting a phase difference of rotation, wherein the rotating part is a center of gravity of each vibrating part of a vibrating body supporting a node of vibration, and the vibrating body has two directions. And vibration detecting means for detecting vibration from one direction.

[Operation] The rotary gyro according to the present invention can be realized by combining two very small motors such as a clock motor. When the stator rotates in the same direction as the rotation axis direction of the rotor with respect to the rotor having a certain inertia rate, the rotation speed of the rotor changes when viewed from the stator serving as the drive detection unit. When viewed from the stator of each of the two motors in the same coordinate system, the two rotors rotating in opposite directions try to maintain a constant rotation speed with respect to the stationary system, so that one of the two rotors has a lower rotation speed and the other has a lower rotation speed. Appears to be spinning faster. The first measuring method of the present invention is to detect a rotation speed difference between two rotors. Next, when the rotation speed of the rotor is adjusted with respect to the stator so as to be constant within a certain time, the difference in rotation speed between the two rotors is gradually eliminated. In this case, since the difference between the rotational speeds of the rotors with respect to the stator is proportional to the rotational phase difference between the two rotors via the restoring force, the rotational speed of the stator is known by measuring the rotational phase difference between the two rotors. I can do it.

As the rotating body, a vibrating body which can vibrate in two directions can be used. Using two vibrating bodies, for example, the first vibrating body is positioned 90 degrees from two directions orthogonal to each other.
Excitation is performed with a phase difference, so that the center of gravity of the vibrating part is rotated clockwise, and the second vibrating body is also orthogonal to each other.
Vibration is performed with a phase difference of -90 degrees from the two directions, and the center of gravity of the vibrating part is rotated counterclockwise. In this state, if the whole vibrating body is rotated clockwise in the same direction as the rotation direction of the center of gravity of the vibrating part of the vibrating body by using the supporting part of the vibrating body, the first vibrating body is caused by inertia with respect to the stationary system. The rotational speed of the center of gravity of the vibrating portion of the vibrating body becomes slow, and the rotational speed of the center of gravity of the vibrating portion of the second vibrating body becomes fast. However, since each of the vibrating bodies performs natural vibration, a restoring force acts on the vibrating body rotated by using the supporting unit so that the rotation speed of the center of gravity of the vibrating unit becomes constant. Therefore, as in the case of the motor, the rotation of the whole vibrating body rotated by using the support part is performed by the vibration phase of the center of gravity of the vibrating part of the first vibrating body and the center of gravity of the vibrating part of the second vibrating body. It can be detected as a difference in vibration phase.

When a vibrating body is used, it can be compared with a general vibrating gyroscope. In a rotating gyro, the inertial force that tries to keep the rotation speed constant with respect to a stationary system is
After all it is Coriolis force. According to D'Alembert's principle, for an object that makes a circular motion in a coordinate system that rotates at a constant speed, the Coriolis force becomes a force that balances with the centrifugal force, and plays a role in keeping the change in the orbit constant against the change in rotation speed. Play. The vibrating gyro vibrates linearly, but since the Coriolis force acts in proportion to the velocity of the center of gravity of the vibrating part, it becomes largest at the position where the amplitude is the smallest and does not work at the position where the amplitude is the largest. On the other hand, in the rotary gyro according to the present invention, since the center of gravity of the vibrating portion of the vibrating body performs a rotating motion,
Always have maximum speed. In the case of the same amplitude, in the case of linear vibration, only a Coriolis force equivalent to the effective value of the alternating current acts in comparison with the case of rotation. In other words, the rotating gyro according to the present invention can detect Coriolis force with an efficiency about 1.4 times higher than that of the vibrating gyro.

Further, when exciting a vibrating gyroscope that performs natural vibration, vibration energy cannot be applied without limit. In a vibrating gyroscope that vibrates linearly, when the vibration amplitude increases, the vibration becomes unstable due to the non-linearity of the restoring force with respect to the amplitude of the vibrating body, and it is not possible to stably continue the vibration with the large amplitude. On the other hand, in the rotary gyro, a stable rotational motion can be continued even with a large amplitude due to the centrifugal force of the center of gravity of the vibrating portion of the rotating vibrating body. Therefore, the rotating gyro can give a large amplitude displacement to the vibrating body with respect to the vibrating gyroscope having the same shape and size.

The rotary gyro has a high Coriolis force detection efficiency for the same amplitude and can generate a large Coriolis force with respect to a vibrating gyro having the same shape and size, so that sufficient detection sensitivity is maintained. In addition, the size of the vibrating gyroscope can be reduced.

[0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a rotary gyro according to a preferred embodiment of the present invention. FIG. 17 is a top view and a circuit block diagram of a motor showing a configuration of a rotary gyro according to an embodiment of the present invention, and FIGS. 14 and 15 are waveform diagrams showing drive detection waveforms of the rotary gyro.

[Description of structure of rotary gyro: FIG. 17] The rotary gyro is composed of a second stator MS1, a first encoder ME1, a second rotor MR2, a second stator MS2, a second encoder ME2, and a drive circuit MD1. ,
It comprises a detection circuit MD2 and a housing MB.

The first rotor MR1 has a cylindrical shape and has an axis MJ1 at the center of the cylinder, and the axis MJ1 is inserted into a bearing of the housing MB. The second rotor MR2 is cylindrical and has an axis MJ2 at the center of the cylinder, and the axis MJ2 is
B is inserted into the bearing. The cylindrical portions of the first rotor MR1 and the second rotor MR2 are made of a permanent magnet such as alnico, samarium cobalt, neodymium iron boron or iron nitride boron, and are magnetized in a direction perpendicular to the central axis of the cylinder.

The first stator MS1 is composed of an electromagnet in which a coil is wound around a soft magnetic material, and the magnetic pole portion of the electromagnet is close to the cylindrical surface of the first rotor MR1 and is directed toward the first rotor MR1. It is arranged and fixed to the housing MB. The second stator MS2 is formed of an electromagnet in which a coil is wound around a soft magnetic material, and the magnetic pole portion of the electromagnet is disposed close to the cylindrical surface of the second rotor MR2 and is arranged toward the second rotor MR2. It is fixed to the housing MB.

The first encoder ME1 is constituted by an electromagnet in which a coil is wound around a soft magnetic material, and the magnetic pole portion of the electromagnet is close to the cylindrical surface of the first rotor MR1 and is directed toward the first rotor MR1. It is arranged and fixed to the housing MB. The second encoder ME2 is configured by an electromagnet in which a coil is wound around a soft magnetic material, and the magnetic pole portion of the electromagnet is close to the cylindrical surface of the second rotor MR2, and is disposed toward the second rotor MR2, It is fixed to the housing MB.

Both ends of the coil winding of the first stator MS1 are connected to the drive circuit MD1, and both ends of the coil winding of the first encoder ME1 are connected to the detection circuit MD2.
, Both ends of the coil winding of the second stator MS2 are connected to the drive circuit MD1, and both ends of the coil winding of the second stator MS2 are connected to the detection circuit MD2.

[Description of Operation and Action of Rotary Gyro: FIG. 1]
4, FIG. 15, FIG. 17, and FIG. 18] The operation of the rotary gyro shown in FIG. 17 is shown. The rotating part of the rotating gyroscope used in the present embodiment is a rotor part of a motor driven electromagnetically. This motor has a mechanism in which a rotor is magnetized in the radial direction, and a rotating force is applied to the rotor by electrically changing the magnetic force of a stator constituted by electromagnets. FIGS. 14, 15 and 18 show detected waveforms of the rotary gyro shown in FIG. In the present embodiment,
In order to cause the rotor to perform constant-speed rotation with less rotation unevenness, a SIN waveform having less cocking than a rectangular waveform is generally used as the waveform of the drive signal generated by the drive circuit.

When the drive circuit MD1 increases the value of the current flowing through the coil of the first stator MS1, for example, the magnetic pole of the electromagnet of the first stator MS1 close to the first rotor MR1 becomes the S pole, for example. Become. Then, the magnetized portion of the first rotor MR1 is attracted to the N pole, and as a result, the first rotor MR1 is rotated by the rotation axis MJ.
Rotate around one. The north pole of the first rotor MR1 is
If the drive current is reversed at an angle passing through the rotation angle closest to the first stator, the first rotor MR1 can be continuously rotated by repeating this operation. The rotation speed of the first rotor MR1 can be determined by the drive frequency | Ω | of the drive circuit MD1. Here, a small magnet MT1 that determines the initial position of the first rotor MR1 is placed on the right side of the first stator MS1 with the N pole facing the first rotor MR1 so that the first rotor MR1 always rotates to the right. To be placed. The small magnet MT1 causes uneven rotation during the continuous rotation of the first rotor MR1.
A mechanism is provided for evacuating to a position away from 1.

When the first rotor MR1 rotates, the first
The magnetic pole of the first rotor MR1 is provided to the coil of the first encoder ME1 which is arranged at a position symmetrical to the first stator MS1 with respect to the rotation axis MJ1 of the rotor MR1 and has the same structure as the first stator MS1. Induced electromotive force is generated due to a change in the distance between the first encoder ME1 and the first encoder ME1.
, A current having the same phase as the current generated by the drive circuit MD1 can be generated.

Next, the operation of the second rotor MR2 will be described. When the value of the current flowing through the coil of the second stator MS2 is increased by the drive circuit MD1, for example, the second
The magnetic pole near the second rotor MR2 of the winding center of the electromagnet of the stator MS2 becomes, for example, the S pole. Then, the magnetized portion is attracted to the N pole of the second rotor MR2, and as a result, the second rotor MR2 is rotated by the rotation axis MJ2.
Rotate around. If the drive current is inverted at an angle at which the N pole of the second rotor MR2 passes through the rotation angle closest to the second stator, this operation is repeated to continuously drive the second rotor MR2. Can be rotated. The rotation speed of the second rotor MR2 can be determined by the drive frequency | Ω | of the drive circuit MD2. Here, a small magnet MT2 for determining the initial position of the second rotor MR2 is placed on the left side of the second stator MS2 with the N pole facing the second rotor MR2 so that the second rotor MR2 always rotates to the left. To be placed. Since the small magnet MT2 causes rotation unevenness while the second rotor MR2 performs continuous rotation, the second rotor MR2
2 is provided with a mechanism for evacuating to a position away from 2.

When the second rotor MR2 rotates, the second rotor MR2
The magnetic pole of the second rotor MR2 is provided to the coil of the second encoder ME2 which is arranged at a position symmetrical to the second stator MS2 with respect to the rotation axis MJ2 of the rotor MR2 and has the same structure as the second stator MS2. Induced electromotive force is generated due to a change in the distance between the second encoder ME2 and the second encoder ME2.
, A current in phase with the current generated by the drive circuit MD2 can be generated.

The first rotor MR1 and the second rotor MR2 generate a sharp rotation speed irregularity called "cocking" at a rotation speed of about one revolution per second, and the first encoder ME1 and the second encoder ME2 have a large rotation speed. The output waveform does not match the current waveform of the drive circuit MD1, but if the rotation speed is increased to several tens of revolutions per second, a clean SIN
The first rotor MR1 and the second rotor MR2 have a stable rotational speed. In the present embodiment, the frequency | Ω | of the drive circuit MD1 is set so that the rotation speed -Ω of the first rotor MR1 and the rotation speed Ω of the second rotor MR2 become several tens of rotations per second or more. I do.

When the housing MB is rotated at the rotation speed ω in the same direction as Ω while the first rotor MR1 is rotating at the rotation speed −Ω and the second rotor MR2 is rotating at the rotation speed Ω, the first rotation is performed. Due to inertia, the first encoder ME1 that rotates at the rotation speed ω together with the housing MB to maintain the rotation speed −Ω with respect to the stationary system due to inertia, the rotation speed of the first rotor MR1 is Observed to be faster than -Ω. That is, from the first encoder ME1,
The rotation speed of the first rotor MR1 is -Ω-ω, that is,-|
Ω + ω |. On the other hand, the second rotor MR2 is rotated by the second encoder ME2 rotating at the rotation speed ω together with the housing MB to maintain the rotation speed Ω with respect to the stationary system due to inertia. Is observed to be slower than Ω. That is, from the second encoder ME2, the rotation speed of the second rotor MR2 is observed as | Ω−ω |.

When the case MB is not rotating, the first encoder ME1 and the second encoder ME2 observe a SIN wave of the frequency | Ω | specified by the drive circuit MD1, and the case MB rotates at the rotational speed. When rotated at ω, the first encoder ME1 observes a SIN wave with an angular frequency | Ω + ω |
The second encoder ME2 has an SIN having an angular frequency | Ω−ω |
While observing the waves, the angular frequency of the output of the first encoder ME1 or the angular frequency of the output of the second encoder ME2 is compared with the angular frequency of the drive of the drive circuit MD1, thereby obtaining the housing MB. The rotation speed ω can be known. For example, FIG. 18 shows the frequency | Ω |
Is shown by a solid line, and a signal B showing a SIN wave whose angular frequency has changed to | Ω + ω | is shown by a dashed line.

When the first rotor MR1 or the second rotor MR2 continues to have an angular frequency difference with respect to the output of the drive circuit MD1, the first rotor MR1 or the second rotor MR2 has a phase difference with respect to the phase of the drive circuit MD1. Second rotor M
The phase of R2 continues to shift, and the first rotor MR1 or the second rotor MR2 with respect to the rotational phase of the drive circuit MD1.
When the rotational phase shift exceeds a certain level, the drive circuit MD
1 is the first rotor MR1 or the second rotor MR2
Cannot be driven. This phenomenon is generally called "step-out". Actually, in a state where the rotation phases of the drive circuit MD1 and the first rotor MR1 or the second rotor MR2 match, the first stator MS1 and the second stator
As in the first encoder ME1 and the second encoder ME2, a counter electromotive force is generated in the stator MS2, and the drive current from the drive circuit MD1 is completely canceled. That is, the drive circuit MD1 does not work at all.
On the other hand, the drive circuit MD1 and the first rotor MR1 or the second rotor
When the rotation phase of the rotor MR2 shifts, this equilibrium state is broken, and the drive circuit MD1 supplies a current to the first stator MS1 and the second stator MS2 to rotate the first rotor MR1 or the second rotor MR2. By changing the speed, the drive circuit MD1 and the first rotor MR1 or the second rotor
A restoring force acts in a direction to make the rotation phases of the rotor MR2 coincide. This restoring force acts to such an extent that the rotational speed ω of the housing MB, the rotational phase of the drive circuit MD1, and the rotational phase of the first rotor MR1 or the second rotor MR2 are substantially proportional to each other.

Therefore, instead of the frequency change, the driving circuit MD
1 and the first rotor MR1 or the second rotor MR2
The rotation speed ω of the housing MB can also be known by measuring the rotation phase difference of Incidentally, it is expected that various accelerations will be applied to the housing MB and the first rotor MR1 or the second rotor MR2. These accelerations become noises in knowing the rotation speed ω of the housing MB. In the present embodiment, as shown in FIG. 17, a first encoder ME1 and a second encoder ME1
2 is input to the detection circuit MD2, and the encoder ME
The rotation speed ω of the housing MB is detected by detecting the phase difference between the outputs of the first and second encoders ME2. The relative rotational phase difference between the first rotor MR1 and the second rotor MR2 is such that the rotational directions of the first rotor MR1 and the second rotor MR2 are opposite, so that noise caused by acceleration other than rotation cancels out. In addition, a phase difference due to rotation is observed twice, and a very good S / N can be detected without being affected by fluctuations of the drive signal of the drive circuit MD1.

A waveform A shown in FIGS. 14 and 15 shows a detected waveform of the first encoder ME1.
A waveform B shown in FIG. 5 indicates a detection waveform of the second encoder ME2. FIG. 14 shows the waveforms of the signals A and B when the housing MB is not rotating by a solid line, and FIG. The waveform of the signal B whose phase is delayed is shown by a broken line. The detection circuit MD2 is indicated by a solid line.
A signal A−B obtained by subtracting the signal A and the signal B, indicated by a solid line, using a signal A + B obtained by adding the signal A and the signal B as a reference signal.
By performing phase detection on B, the rotation speed ω of the housing MB is detected.

In this embodiment, for the sake of simplicity, a single-pole motor is used, in which one stator is arranged with respect to the rotor. A multi-pole motor arranged in a large number may be used. Although an independent electromagnet is used as the encoder, the stator itself may be used as the encoder, and a phase shift may be observed from a composite waveform of the drive waveform and the detection waveform, or the encoder may be an optical type. .

In the present embodiment, the above-described configuration is used in order to accurately detect the rotational speed ω of the housing MB. However, as a rough detection, only the first rotor MR1 is used. , The first rotor MR1 is kept stationary without rotating with respect to the stationary system, and the rotation angle of the first rotor MR1 is detected simply by using the first encoder ME1. The rotation speed ω can be detected.

(Second Embodiment) An embodiment according to the best mode for carrying out the rotary gyro of the present invention will be described below with reference to the drawings. FIGS. 4, 5 and 14 to 16
FIGS. 19 to 22 show a rotary gyro according to a second embodiment of the present invention. FIGS. 4 and 5 are perspective views for explaining a mechanism of deformation of a piezoelectric element. FIGS. FIG. 16 is a waveform diagram showing a signal from the element, FIG. 16 is an operation explanatory diagram expressing a signal from the piezoelectric element by a vector, and FIG. 19 shows an appearance of a vibrating gyroscope, FIG. 20 is a perspective view showing coordinates used in the following description, FIG. 20 is a front view of a film used for support, and FIG. FIG. 22 is an operation explanatory view schematically showing a cross section of a vibration antinode of the sound piece B10 viewed from the tip side of the sound piece B10.

[Description of Structure of Rotary Gyro: FIGS. 19 to 2]
1] As shown in FIG. 19, the sound piece B10 is made of a columnar elastic material having a square cross section. The column is made of metal or quartz glass having elasticity. The column has a square cross section.
1 and B24. Two support positions B12 and B13 indicated by broken lines are intersections of a cross section orthogonal to the direction in which the column extends and the side surface of the column,
It is located at the node of the primary vibration of the sound piece B10.

The support portions B14 and B15 shown in FIG.
Films B14M and B which have a planar shape, have supporting frames B14W and B15W in the periphery, and have holes B14H and B15H having the cross-sectional shape of the sound piece B10 in the center, and have elasticity.
15M, and the films B14M and B15M are made of Mylar film, FPC or rubber film, and are arranged in a direction perpendicular to the direction in which the columns of the sound piece B10 extend, and the sound piece B10
Are the respective holes B14H and B1 of the support portions B14 and B15.
5H, and joined to two support positions B12 and B13 in the node of the primary vibration of the sound piece B10 shown in FIG.

The metal used in the second embodiment is
An alloy containing 50% of iron, 35% of nickel, and 9.1% of chromium, whose temperature dependence of the elastic modulus is very small, is called an elinvar. Similarly, when using quartz glass, which has very low temperature dependence of the elastic modulus, a thin film of conductive material such as silver or chromium is formed on a part of the surface in advance by electroless plating or vapor deposition, etc. The common electrode of the piezoelectric element is used.

In the following description of the sound piece B10, the coordinate axes Y, Z and X are set in directions parallel to the respective sides. At this time, the longitudinal direction, that is, the direction in which the column is extended is the Y axis,
Let the width direction be the Z axis and the thickness direction be the X axis. The length direction, width direction and thickness direction of the sound piece B10 thus determined are as follows.
They are parallel to the Y axis, Z axis and X axis, respectively. However, since the sound piece B10 has a symmetrical shape in the XZ plane, the terms width and thickness used herein have no special meaning. In the following, the term width in the X or Z direction or simply the width of the column will be used.

FIG. 19 shows, as an example, a state in which the piezoelectric element B22 and B23, and a drive section and a detection section composed of the piezoelectric elements B21 and B24, which are not shown in the perspective view, are bonded to the side surfaces of the pillar. The piezoelectric element has a thin plate shape, and an alloy such as silver or chromium is vapor-deposited on both surfaces in advance. An epoxy-based conductive adhesive is applied to one side of the piezoelectric element and attached to four sides of the pillar.

FIG. 21 shows an XZ cut of the column and the piezoelectric element having the shape shown in FIG.
Shown in cross section. For driving, a piezoelectric element B21 is attached to the first side face of the sound piece B10, and the piezoelectric element B21 is attached to the second side face.
22 is attached. For detection, the sound piece B10
The piezoelectric element B23 is attached to the third side surface, and the piezoelectric element B24 is attached to the fourth side surface.

FIG. 21 shows driving piezoelectric elements B21 and B22.
Oscillating circuit BHC0 that oscillates the sound piece B10, delays the oscillating phase of the oscillating circuit BHC0 by 90 degrees, adds a phase shift circuit BL that adjusts the amplitude, and adds the signals of the oscillating circuit BHC0 and the detecting piezoelectric element B23. A circuit BK0, a phase shift circuit BI0 for changing the phase of the added signal, a binarization circuit BC0 for binarizing the shifted signal, and an oscillation circuit BHC0
And a lock-in amplifier BP0 that performs phase detection on the subtracted signal using a reference signal and converts the signal into a DC voltage, and a subtraction circuit BG0 that subtracts each signal of the detection piezoelectric element B23.
The wiring between them is shown.

[Description of operation and action of rotary gyro: FIG.
5, 14, 15, 16, 19, 20, and 2
1 and 22] FIGS. 4 and 5 show the operation of the piezoelectric element.
When a piezoelectric element called PZT used in the present embodiment is polarized by applying a high voltage in advance, the direction of strain varies depending on the direction of the voltage applied to the piezoelectric element. The (+) plane 58 shown in FIG. 4 is a plane to which a positive voltage is applied to the back side during polarization, and when the back side is set to a high potential, the thickness increases and the length and width shrink. FIG. 5 shows a (−) surface 59 which is a back surface of the surface 58. When a positive voltage is applied to the (-) surface 59, the thickness of the (-) surface 59 is reduced, and the length and width are increased.
The sign of (+) or (-) written in FIG.
It shows which of the surfaces of the piezoelectric element adhered to each side surface of the ten columns is the surface adhered to the side surface of the column. The lines outside the drawing schematically show the wiring between the electrodes of each piezoelectric element.

In FIG. 21, the oscillation circuit BHC0 has an accurate reference clock using, for example, a crystal oscillator, and can generate a SIN waveform having a stable frequency. From the oscillation circuit BHC0, S is applied to the electrode of the piezoelectric element B21.
When an AC voltage having an IN waveform is applied, for example, the piezoelectric element B
21 contracts in the Y direction, resulting in bending displacement in the X axis direction. This direction changes with the passage of time, and as a result, the sound piece B10 bends and vibrates in the X-axis direction.

In FIG. 21, when an AC voltage having a -COS waveform is applied to the electrode of the piezoelectric element B22 by delaying the phase by 90 degrees by the phase shift circuit BL from the oscillation circuit BHC0,
For example, the piezoelectric element B22 contracts in the Y direction, and as a result, bending displacement occurs in the Z axis direction. As time passes, this direction changes, and as a result, the sound piece B10 bends and vibrates in the Z-axis direction. Here, the AC voltage from the oscillation circuit BHC0 is not applied directly to the electrode of the piezoelectric element B22, but is delayed by 90 degrees by the phase shift circuit BL and is input to the electrode of the piezoelectric element B22 as a -COS waveform. Therefore, the bending vibration in the Z direction is a bending vibration delayed by 90 degrees with respect to the bending vibration in the X direction.

FIG. 22 schematically shows the state of the bending vibration of the sound piece B10 when the bending vibration in the X direction and the bending vibration in the Z direction are simultaneously present. This is called a first rotational movement.
In the circuit configuration of FIG. 21, one oscillation circuit BHC0
Are used to excite bending vibration in the X direction and bending vibration in the Z direction with voltage outputs having the same frequency and amplitude. At this time, the oscillation frequency Bf1 of the bending vibration in the X direction and the oscillation frequency Bf2 of the bending vibration in the Z direction are the same frequency Bf, and the first rotational motion is generated as a combination of the bending vibration in the X direction and the bending vibration in the Z direction. I do. As a result of the phase shift of the bending vibration in the Z direction being delayed by 90 degrees with respect to the bending vibration in the X direction, the motion of the sound piece B10 is not a vibration but a counterclockwise rotation. In the present embodiment, a square prism having a square cross section is used for the sound piece B10. However, in actuality, the natural frequency of the bending vibration in the X direction and the natural frequency of the Z Since the natural frequencies of the bending vibration of the oscillation circuit BHC0 do not match, depending on how to select the oscillation frequency Bf of the oscillation circuit BHC0, X
The amplitude of the bending vibration in the direction does not match the amplitude of the bending vibration in the Z direction.
The phase also becomes unstable. In FIG. 22, the oscillation circuit BH
The oscillation frequency Bf of C0 is adjusted, the phase shift amount of the phase shift circuit BL is adjusted, the amplitude of the bending vibration in the X direction is matched with the amplitude of the bending vibration in the Z direction, and the first rotational motion in the case of a circular orbit is obtained. I'm drawing. Hereinafter, the oscillation frequency Bf may be written as the rotation speed | Ω |.

In the first rotational motion shown in the present embodiment, the whole sound piece B10 is not rotating, but the center of gravity of the XZ cross section of the sound piece 10 at the antinode of vibration makes a rotational movement.
This is a rotational movement of the center of gravity of the X-Z section of the sound piece 10. Hereinafter, the first rotational movement may be expressed as a rotational movement of the center of gravity of the vibrating portion of the sound piece 10.

When the first rotational motion is occurring, the sound piece B
When the whole 10 rotates counterclockwise around the Y-axis at an angular velocity ω, the sound piece B10 receives Coriolis force in a direction orthogonal to the direction of displacement, but if the first rotational movement is a circular movement, the sound piece B10 The rotation trajectory of the center of gravity of the vibrating portion of the sound piece B10 does not change even when viewed from the coordinate system rotating at the angular velocity ω to which In other words, the Coriolis force acting on the first rotational motion that draws the circular trajectory shown in FIG. 22 acts as a force that balances the centrifugal force in the direction opposite to the centrifugal force, so that the rotational speed of the first rotational motion | Even if Ω | changes by ω in the coordinate system rotating at the angular velocity ω to which the sound piece B10 belongs, the amplitude of the sound piece B10 does not change because the motion of the sound piece B10 maintains inertia with respect to the stationary system. . That is, when the first rotational motion is generated, the effect of the entire sound piece B10 rotating at the angular velocity ω around the Y axis is due to the detection piezoelectric element B23 or B24 attached to the sound piece B10. Is observed as a change in the frequency of the first rotational movement with respect to the frequency Bf of the drive signal generated by the oscillation circuit BHC0.

Strictly speaking, if the rotation center of the coordinate system in which the sound piece B10 rotates at the angular velocity ω does not coincide with the center of the first rotational movement, the trajectory changes, but the rotation speed ω of the entire sound piece B10 is changed.
However, when the rotation speed is very small as compared with the rotation speed Ω of the first rotation movement, it can be ignored. In the present embodiment, the rotational speed Ω of the first rotational movement is from 5000 HZ to 30000 H.
In contrast to Z, since the upper limit of the rotational speed ω of the entire sound piece B10 is about 0.25 HZ, the trajectory of the first rotational movement may not be changed.

However, the sound piece B10 driven by the oscillation circuit BHC0 is driven at the oscillation frequency Bf in the X direction and the Z direction. Accordingly, the rotational speed of the first rotational movement is also returned to Bf in a state where the Coriolis force does not act. This resilience is
The rotation speed ω of the entire sound piece B10 and the phase shift of the detection piezoelectric element B23 from the output of the drive circuit BHC0 work so as to be approximately proportional. Therefore, the rotational speed ω of the entire sound piece B10 can be known by measuring the phase difference between the driving circuit BHC0 and the detecting piezoelectric element B23 instead of the frequency change.

The rotation speed Ω of the center of gravity of the vibrating part of the sound piece B10
Is returned to the oscillation frequency Bf of the oscillation circuit BHC0. As a result, the rotation speed Ω of the center of gravity of the vibrating portion of the sound piece B10 changes by the rotation speed ω of the entire sound piece B10 when viewed from a stationary system.
As a result, it rotates at the rotational angular velocity Ω-ω. Therefore, in an equilibrium state in which a phase shift occurs due to the rotation speed ω of the entire sound piece B10, the trajectory of the rotational motion of the center of gravity of the vibrating portion of the sound piece B10 slightly changes due to a change in centrifugal force. At this time, the radius of the rotational movement of the center of gravity of the vibrating portion of the sound piece B10 decreases. To detect the Coriolis force, use X
Alternatively, a change in the amplitude of the bending vibration in the Z direction can be used, but the change in the amplitude is slight. In the present embodiment, a method of measuring the phase shift of the signal of the detection piezoelectric element B23 from the oscillation circuit BHC0 will be described.

In FIG. 21, the output of the oscillation circuit BHC0 for driving the vibrating piezoelectric element B21 is represented by the signal A and the sound piece B10.
An output from the electrode portion of the piezoelectric element B23 for detecting the vibration in the X direction is defined as a signal B. The first rotational movement of the sound piece B10 has bending vibration in the X direction as a component in the X direction. In the sound piece B10 rotating counterclockwise, the voltage output B from the detecting piezoelectric element B23 of the sound piece B10 that reflects the bending vibration in the X direction exerts a Coriolis force due to the counterclockwise rotation ω of the whole sound piece B10. At this time, the output signal A of the oscillation circuit BHC0 is
The phase is delayed. In the present embodiment, the signal A and the signal B are input to an addition circuit BK0 and a subtraction circuit BG0, and a sum signal A + B of the signal A and the signal B and a difference signal AB are generated and used.

FIG. 14 shows the relationship between the signals A, B, A + B, and AB when the signal A is adjusted so as to have the same amplitude as the signal B and the Coriolis force does not work. In this case, each of the signal A and the signal B is a bending vibration itself in the Z direction, and these are completely matched signals.
Signal A + B is a signal having twice the amplitude of signals A and B, and signal AB has no amplitude.

FIG. 15 shows the relationship among the signals A, B, A + B and AB when the first rotational movement has a phase difference from the drive signal of the oscillation circuit BHC0 due to the Coriolis force.
The effect of the Coriolis force changes the relative phases of the signal A indicated by the dashed line and the signal B indicated by the broken line. The relative phases of the signal A and the signal B change substantially in proportion to the rotation speed ω of the entire sound piece B10. If the phase of the signal B is delayed by the rotation speed ω of the entire sound piece B10, the sound piece B10
The phase of the signal B advances with respect to the entire rotation speed -ω, and the change in the phase of the signals A and B changes with the rotation speed ω of the entire sound piece B10.
Depends on the direction of rotation. On the other hand, regardless of the presence or absence of the Coriolis force, the signals A + B and AB shown by solid lines maintain the phase when the Coriolis force does not work. The Coriolis force is
This causes a small change in the amplitude of the signal A + B, and generates a small amplitude in the signal AB.

FIG. 16 shows the relationship among the signals A, B, A + B and AB using vectors. In this case, the amplitude of the signal is represented by the length of the vector, and the phase is represented by the rotation of the vector. The effect of the Coriolis force can be detected as a change in the amplitude of the signals A + B and AB. It should be noted here that when the signal A and the signal B change only in phase and the amplitude does not change, the relative phase relationship between the signals A + B and AB is always 90 degrees regardless of the magnitude of the Coriolis force. Is to be kept.

In the present embodiment, a lock-in amplifier is used to detect a small output Coriolis force, and only the same frequency components as the reference signal are extracted from the detected signal and integrated to obtain a high S / N ratio. Try to realize
In this case, an accurate reference signal having the same phase as the detected signal is required. First, the signals A, B, and A + B as detected signals reflecting the Coriolis force have a large output even in the absence of the Coriolis force, and thus are not suitable for capturing a change due to a small Coriolis force. On the other hand, since the signal AB does not have an output when there is no Coriolis force, it is most suitable as a detected signal in consideration of a dynamic range, and is used. On the other hand, as the reference signal, the signals A and B cannot be used because the phase changes due to the Coriolis force, and the AB signal having the most accurate phase itself has no AC output or is unstable when the Coriolis force does not work or is small. So you can't use it. However, as shown in FIG. 16, the A + B signal always has a stable large amplitude and a phase difference that is exactly 90 degrees different from the AB signal. Therefore, a signal obtained by shifting the phase of the A + B signal by 90 degrees is used as the reference signal.

As shown in FIG. 21, the signal A and the signal B are input to a subtraction circuit BG0 and input to a lock-in amplifier BP0. Further, the signal A and the signal B are input to the adder BK0, the phase is shifted by 90 degrees by the phase shifter BI0, and the binarization circuit BC0 is output.
Generates a switching signal at the lock-in amplifier BP0.
As a reference signal. As a result, the AB signal becomes A
+ B signal is full-wave rectified at the timing shifted by 90 degrees,
Converted to DC output. With this configuration, most signal components other than the frequency of the reference signal regarded as noise are removed, and Coriolis force detection with very good S / N can be realized.

Therefore, only the phase difference between the detecting piezoelectric element B23 of the sound piece B10 for detecting the bending vibration in the X direction and the oscillation circuit BHC0 is extracted as a direct current. Thus, the value of the angular velocity ω can be accurately known.

The sound piece B10 in this embodiment can be operated as a vibrating gyroscope. In this case, for example, if the phase shift amount of the phase shift circuit BL is set to 0 degree, the sound piece 10 can be vibrated linearly. It does not work at the position where the amplitude is maximum. On the other hand, in the rotary gyro according to the present embodiment, since the sound piece B10 performs a rotary motion, it always has the maximum speed. When the sound piece B10 has the same amplitude, in the case of linear vibration, only a Coriolis force of about the same as the effective value of the alternating current acts as compared with the case of rotation. In other words, the rotating gyro in the present embodiment can detect the Coriolis force with an efficiency about 1.4 times higher than that of the vibrating gyro.

Further, when exciting a vibrating gyroscope that performs a natural vibration, the vibration energy cannot be applied without limit. In a vibrating gyroscope that vibrates linearly, when the vibration amplitude increases, the vibration becomes unstable due to the non-linearity of the restoring force with respect to the amplitude of the vibrating body, and it is not possible to stably continue the vibration with the large amplitude. On the other hand, in a rotary gyro, a stable rotational motion can be continued even with a large amplitude due to the centrifugal force of the rotating vibrating body. Therefore, the rotating gyro can give a large amplitude displacement to the vibrating body with respect to the vibrating gyroscope having the same shape and size.

The rotary gyro according to the present embodiment has a higher Coriolis force detection efficiency for the same amplitude and generates a larger Coriolis force than, for example, a vibrating gyro using the sound piece 10 used in the present embodiment as it is. Can be done. Therefore, the size can be reduced while maintaining sufficient detection sensitivity with respect to the vibrating gyroscope.

(Third Embodiment) Hereinafter, a preferred embodiment of a rotary gyro according to the present invention will be described with reference to the drawings. FIG. 4, FIG. 5, FIG.
6, FIGS. 19 to 20, and FIGS. 22 to 24 show a rotary gyro according to a third embodiment of the present invention, and FIGS. 4 and 5 are perspective views for explaining a mechanism of deformation of a piezoelectric element. , FIGS. 14 and 15 are waveform diagrams showing signals from the piezoelectric element, FIG. 16 is an operation explanatory diagram expressing the signal from the piezoelectric element by a vector, and FIG. 19 is an external view of a sound piece type vibration gyro. FIG. 20 is a perspective view showing a piezoelectric element and a support portion, and showing coordinates used in the following description. FIG. 20 is a front view of a film used for support, and FIGS. 22 and 23 are front views of the sound piece B10. FIG. 24 is an operation explanatory view schematically showing a cross section of the antinode of the vibration of the sound piece B10 as viewed. FIG. It is.

[Description of Structure of Rotary Gyro: FIGS. 19 to 2]
0 and FIG. 24] In the present embodiment, two sound pieces B10 and B11 are used as a rotating gyro. Since the sound piece B10 and the sound piece B11 have exactly the same shape and structure, the shape and structure of the sound piece will be described below.
FIG. 24 shows only the connection with the circuit. As shown in FIG. 19, the sound piece B10 is formed of a columnar elastic material having a square cross section. The column is made of metal or quartz glass having elasticity. The column has a square cross section.
It has a drive unit and a detection unit consisting of 21 and B24. Two support positions B12 and B13 indicated by broken lines are intersections of a cross section orthogonal to the direction in which the column extends and the side surface of the column,
It is located at the node of the primary vibration of the sound piece B10.

The support portions B14 and B15 shown in FIG.
Films B14M and B which have a planar shape, have supporting frames B14W and B15W in the periphery, and have holes B14H and B15H having the cross-sectional shape of the sound piece B10 in the center, and have elasticity.
15M, and the films B14M and B15M are made of Mylar film, FPC or rubber film, and are arranged in a direction perpendicular to the direction in which the columns of the sound piece B10 extend, and the sound piece B10
Are the respective holes B14H and B1 of the support portions B14 and B15.
5H, and joined to two support positions B12 and B13 in the node of the primary vibration of the sound piece B10 shown in FIG.

The metals used in this embodiment are iron 50% and nickel 35 whose temperature dependence of elastic modulus is very small.
% And an alloy containing 9.1% chromium, which is referred to as Elinvar. Similarly, when using quartz glass, which has very low temperature dependence of the elastic modulus, a thin film of conductive material such as silver or chromium is formed on a part of the surface in advance by electroless plating or vapor deposition, etc. The common electrode of the piezoelectric element is used.

In the following description of the sound piece B10, the coordinate axes Y axis, Z axis and X axis are set in directions parallel to each side. At this time, the longitudinal direction, that is, the direction in which the column is extended is the Y axis,
Let the width direction be the Z axis and the thickness direction be the X axis. The length direction, width direction and thickness direction of the sound piece B10 thus determined are as follows.
They are parallel to the Y axis, Z axis and X axis, respectively. However, since the sound piece B10 has a symmetrical shape in the XZ plane, the terms width and thickness used herein have no special meaning. In the following, the term width in the X or Z direction or simply the width of the column will be used.

FIG. 19 shows, as an example, a state in which the piezoelectric element B22 and the piezoelectric element B23 and the drive section and the detection section composed of the piezoelectric elements B21 and B24 which are not shown in the perspective view are adhered to the side surfaces of the pillar of the sound piece B10. . The piezoelectric element has a thin plate shape, and an alloy such as silver or chromium is vapor-deposited on both surfaces in advance. An epoxy-based conductive adhesive is applied to one side of the piezoelectric element and attached to four sides of the pillar.

FIG. 24 shows a column and a piezoelectric element having the shape shown in FIG. 19 in an XZ cross section in which the sound piece B10 and the sound piece B11 are cut at the antinode of the primary vibration. For driving, sound piece B1
The piezoelectric element B21 is attached to the first side surface of the sound piece B11, the piezoelectric element B22 is attached to the second side surface, the piezoelectric element B25 is attached to the first side surface of the sound piece B11, and the piezoelectric element B26 is attached to the second side surface. is there. For detection, the sound piece B1
The piezoelectric element B23 is attached to the third side surface of the sound element B0, the piezoelectric element B24 is attached to the fourth side surface, the piezoelectric element B27 is attached to the third side surface of the sound piece B11, and the piezoelectric element B28 is attached to the fourth side surface. is there.

FIG. 24 shows driving piezoelectric elements B21 and B22.
Oscillates the resonating piece B10 using the piezoelectric element B2 for driving.
5 and B26, an oscillating circuit BH0 for oscillating the sound piece B11, and piezoelectric elements B23 and B25 for detection as supply sources of a feedback signal for continuing self-excited oscillation, delaying the phase of the oscillating circuit BH0 by 90 degrees. Phase shift circuits BL1 and BL2 for adjusting the amplitude, and piezoelectric elements B24 and B28 for detection
Adder BK0 for adding the respective signals, a phase shifter BI0 for changing the phase of the added signal, and 2
And a lock-in amplifier BP0 for phase-detecting the subtracted signal using a reference signal and converting the signal into a DC voltage. And the wiring between them.

[Description of Operation and Action of Rotary Gyro: FIG.
5, 14, 15, 16, 19, 20, and 2
2, 23 and 24] FIGS. 4 and 5 show the operation of the piezoelectric element. When a piezoelectric element called PZT used in this embodiment is polarized by applying a high voltage in advance, the direction of strain differs depending on the direction of the voltage applied to the piezoelectric element. The (+) plane 58 shown in FIG. 4 is a plane to which a positive voltage is applied to the back side during polarization, and when the back side is set to a high potential, the thickness increases and the length and width shrink. Also, FIG.
8 shows a (−) surface 59 which is the back surface of the substrate 8. (-) Face 59
When a positive voltage is applied to the back surface, the thickness decreases and the width and length increase. The symbol (+) or (-) written in FIG. 25 indicates which of the surfaces of the piezoelectric element adhered to each side surface of the column of the sound piece B10 is the surface adhered to the side surface of the column. Is shown. The lines outside the drawing schematically show the wiring between the electrodes of each piezoelectric element.

In FIG. 24, when a voltage is applied from the oscillation circuit BH0 to the electrodes of the piezoelectric elements B21 and B27, for example, the piezoelectric elements B21 and B27 contract in the Y direction, and as a result, bending displacement occurs in the X-axis direction. The oscillation circuit BH0 is
Amplify the voltage from the electrodes B23 and B25 of the piezoelectric element,
As time elapses, this direction changes, and as a result, the sound pieces B10 and B11 self-oscillate in bending vibration in the X-axis direction.

When the sound pieces B10 and B11 self-oscillate in the X-axis direction, the oscillation circuit BH0 outputs a signal from the piezoelectric element B2.
When a voltage is applied to the electrodes 2 and B26, for example, the piezoelectric elements B22 and B26 contract in the Y direction, and as a result, bending displacement occurs in the Z axis direction. The oscillation circuit BH0 amplifies the voltage from the electrodes B23 and B25 of the piezoelectric element, and this direction changes over time, and as a result, the sound piece B1
0 and the sound piece B11 bend and vibrate in the Z-axis direction. However,
Here, the AC voltage from the oscillation circuit BH0 is not directly applied to the electrodes of the piezoelectric elements B22 and B26, but the phase is delayed by 90 degrees by the phase shift circuits BL1 and BL2, the voltage is adjusted, and the electrodes of the piezoelectric elements B22 and B26 are adjusted. Is being entered. Therefore, the bending vibration in the Z direction is a bending vibration delayed by 90 degrees with respect to the bending vibration in the X direction.

FIG. 22 schematically shows the state of the bending vibration of the sound piece B10 when the bending vibration in the X direction and the bending vibration in the Z direction are simultaneously present. This is called a first rotational movement.
In the circuit configuration of FIG. 21, one oscillation circuit BH0 is used to excite bending vibration in the X direction and bending vibration in the Z direction with voltage outputs having the same frequency and amplitude. At this time, the oscillation frequency Bf1 of the bending vibration in the X direction and the oscillation frequency Bf2 of the bending vibration in the Z direction are the same frequency Bf, and the first rotational motion is generated as a combination of the bending vibration in the X direction and the bending vibration in the Z direction. I do. As a result of the phase shift of the bending vibration in the Z direction being delayed by 90 degrees with respect to the bending vibration in the X direction, the motion of the sound piece B10 is not a vibration but a counterclockwise rotation. In this embodiment, a quadrangular prism having a square cross section is used for the sound piece B10. However, in actuality, the natural frequency of the bending vibration in the X direction and the natural frequency of the Z Since the natural frequencies of the bending vibrations do not match, the amplitude of the bending vibration in the X direction does not match the amplitude of the bending vibration in the Z direction depending on how the oscillation frequency Bf of the oscillation circuit BH0 is selected, and the phase becomes unstable. In FIG. 22, the oscillation circuit BH0
The oscillation frequency Bf is adjusted, the phase shift amount of the phase shift circuit BL1 is adjusted, the amplitude of the bending vibration in the X direction and the amplitude of the bending vibration in the Z direction are matched, and a first rotational motion in the case of a circular orbit is drawn. ing. Hereinafter, the oscillation frequency Bf may be written as the rotation speed | Ω |.

In the first rotational movement shown in the present embodiment, the entire sound piece B10 is not rotating, but the center of gravity of the X-Z cross section of the sound piece 10 at the antinode of vibration makes a rotational movement.
This is a rotational movement of the center of gravity of the X-Z section of the sound piece 10. Hereinafter, the first rotational movement may be expressed as a rotational movement of the center of gravity of the vibrating portion of the sound piece 10.

FIG. 23 schematically shows the state of the bending vibration of the sound piece B11 when the bending vibration in the X direction and the bending vibration in the Z direction are simultaneously present. This is called a second rotational movement.
In the circuit configuration of FIG. 24, one oscillation circuit BH0 is used to excite bending vibration in the X direction and bending vibration in the Z direction with voltage outputs having the same frequency. At this time, the oscillation frequency Bf3 of the bending vibration in the X direction and the oscillation frequency Bf4 of the bending vibration in the Z direction are the same frequency Bf, and a rotational motion is generated as a combination of the bending vibration in the X direction and the bending vibration in the Z direction. As a result that the phase shift of the bending vibration in the Z direction is delayed by 90 degrees with respect to the bending vibration in the X direction, the motion of the sound piece B11 is not a vibration but a clockwise rotation. In the present embodiment, a square prism having a square cross section is used for the sound piece B11.
In reality, the natural frequency of the bending vibration in the X direction does not match the natural frequency of the bending vibration in the Z direction due to variations in machining accuracy and the position at which the piezoelectric element is stuck, so depending on how the oscillation frequency Bf of the oscillation circuit BH0 is selected, X The amplitudes of the bending vibration in the direction and the bending vibration in the Z direction do not match, and the phase becomes unstable. FIG. 23 illustrates a second rotational motion in the case of a circular orbit by adjusting the phase shift amount and the amplitude of the phase shift circuit BI2 so that the amplitude of the bending vibration in the X direction matches the amplitude of the bending vibration in the Z direction. I have. Thereafter, the oscillation frequency Bf is changed to |
−Ω |.

In the second rotational movement shown in the present embodiment, the entire sound piece B11 is not rotating, but the center of gravity of the XZ cross section of the sound piece 11 at the antinode of vibration performs a rotational movement.
This is the rotational motion of the center of gravity of the X-Z section of the sound piece 11. Hereinafter, the second rotational movement may be referred to as a rotational movement of the center of gravity of the vibrating portion of the sound piece 11.

When the first rotary motion and the second rotary motion are generated, when the sound piece B10 and the sound piece B11 rotate counterclockwise around the Y axis at the rotation speed ω, the sound piece B10 and the sound piece B10 The center of gravity of the vibrating part of B11 receives Coriolis force in a direction orthogonal to the direction of displacement, but in the case of a circular motion, the sound piece B10 and the sound piece also look at the coordinate system rotating at the rotation speed ω to which the sound piece B11 belongs. The trajectories of the centers of gravity of the vibrating parts of B10 and the sound piece B11 do not change. In other words, the Coriolis force acting on the first rotational movement that draws a circular orbit shown in FIG. 22 and the Coriolis force acting on the second rotational movement that draws a circular orbit shown in FIG.
Since the centrifugal force acts in a direction opposite to the centrifugal force and acts as a force, the rotational frequency Bf of the first rotational motion and the second rotational motion depends on the motion of the sound piece B10 and the sound piece B11 with respect to the stationary system. In order to maintain the inertia, the amplitude of the center of gravity of the vibrating part of the sound piece B10 and the sound piece B11 does not change even if it changes by the rotation speed ω when viewed from the coordinate system rotating at the rotation speed ω to which the sound piece B10 and the sound piece B11 belong. do not do. That is, when the first rotary motion and the second rotary motion are occurring, the sound piece B10 and the sound piece B1
1 is rotated around the Y axis at a rotational speed ω. The effect of the driving signal generated by the oscillation circuit BH0 is obtained from the detecting piezoelectric elements B24 and B28 attached to the sound pieces B10 and B11. The change in the frequency of the first rotational motion and the second rotational motion relative to Bf is observed as | ω |. However, as for the frequency change, when ω is counterclockwise, the frequency of the first rotational motion becomes smaller and the frequency of the second rotational motion becomes larger.

Strictly speaking, when the center of rotation of the coordinate system in which the sound piece B10 rotates at the angular velocity ω does not coincide with the center of the first rotational movement, the trajectory of the center of gravity of the vibrating portion of the sound piece B10 changes. If the rotation speed ω of the entire piece B10 is very small compared to the rotation speed Ω of the first rotation motion, it can be ignored.
In the present embodiment, the rotational speed Ω of the first rotational motion
Is from 5000HZ to 30,000HZ,
Since the upper limit of the rotational speed ω of the entire sound piece B10 is about 0.25 HZ, the trajectory of the first rotational movement may not be changed.

Similarly, when the center of rotation of the coordinate system in which the sound piece B11 rotates at the rotation speed ω does not coincide with the center of the second rotational movement, the trajectory of the center of gravity of the vibrating portion of the sound piece B11 changes. If the rotation speed ω of the entire piece B11 is very small compared to the rotation speed −Ω of the second rotation motion, it can be ignored. In the present embodiment, the rotational speed Ω of the second rotational movement is from 5000 Hz to 30000 Hz, whereas the rotational speed ω of the entire sound piece B11 has an upper limit of about 0.25 HZ. The trajectory of the rotational movement of may be unchanged.

The sound piece B10 and the sound piece B11 have the oscillation circuit B
Using H0, self-excited oscillation is performed at an oscillation frequency Bf near the natural frequency of the sound piece in the X direction and the Z direction. Accordingly, the rotational frequencies of the first rotational movement and the second rotational movement are also returned to Bf when the Coriolis force does not act. This resilience is
The rotational speed ω of the entire sound piece B10 and the sound piece B11, the phase delay of the detecting piezoelectric element B24 reflecting the first rotational movement, and the phase advance of the detecting piezoelectric element B28 reflecting the second rotational movement. , And the phase difference between the detecting piezoelectric elements B24 and B28 is substantially proportional. Therefore, by measuring not the frequency change but the phase difference between the detection piezoelectric elements B24 and B28, the rotation speed ω of the entire sound piece B10 and the sound piece B11 can also be known.

The rotation speed Ω of the center of gravity of the vibrating portion of the sound piece B10 and the rotation speed −Ω of the center of gravity of the vibrating portion of the sound piece B11 are returned to the oscillation frequency Bf of the oscillation circuit BH0.
When viewed from a stationary system, the rotational speed of each of the centroids of the vibrating part of the sound piece B10 and the vibrating part of the sound piece B11 changes by the rotational angular velocity ω of the whole vibrating part of the sound piece B10 and the vibrating part of the sound piece B10. Will rotate at the speed-| Ω-ω |
The center of gravity of the vibrating portion of the sound piece B11 rotates at the rotation speed Ω + ω. Therefore, in an equilibrium state in which a phase shift occurs due to the rotation speed ω of the entire sound piece B10 and the sound piece B11,
The trajectory of the rotational motion of the center of gravity of the vibrating portions of the sound piece B10 and the sound piece B11 slightly changes due to a change in centrifugal force. At this time, the radius of the first rotational movement of the sound piece B10 decreases, and the radius of the second rotational movement of the sound piece B11 increases. For the detection of the Coriolis force, the relative change of the amplitude of the bending vibration of the sound piece B10 and the sound piece B11 in the X or Z direction can be used, but the change of the amplitude is slight. In the present embodiment, a method of measuring the phase difference using the signals of the detecting piezoelectric elements B24 and B28 will be described.

In FIG. 24, the output from the electrode portion of the piezoelectric element B28 for detecting the vibration of the sound piece B11 in the Z direction is a signal A, and the piezoelectric element B2 for detecting the vibration of the sound piece B10 in the Z direction.
The output from the electrode unit 4 is signal B. The first rotational movement of the sound piece B10 has bending vibration in the Z direction as a component in the Z direction. In the sound piece B10 rotating counterclockwise, Z
The phase of the voltage output B from the detecting piezoelectric element B24 of the sound piece B10 reflecting the bending vibration in the direction is delayed when the Coriolis force acts due to the counterclockwise rotation ω of the whole sound piece B10. On the other hand, in the sound piece B11 rotating clockwise, the piezoelectric element B28 for detecting the sound piece B11 reflecting the bending vibration in the Z direction.
Is the counterclockwise rotation ω of the entire speech piece B11.
When the Coriolis force acts, the phase advances. In the present embodiment, the signal A and the signal B are input to the addition circuit K0 and the subtraction circuit G0, and the sum signal A + B of the signal A and the signal B and the difference signal AB are generated and used.

FIG. 14 shows the relationship between the signals A, B, A + B and AB when the Coriolis force does not act by a solid line. In this case, the signal A and the signal B are bending vibrations themselves in the Z direction, and these are the phase shift circuits BL1 and BL2 shown in FIG.
The signal is completely matched by the adjustment of the amplitude and the phase by the above. Signal A + B is a signal having twice the amplitude of signals A and B, and signal AB has no amplitude.

FIG. 15 shows the relationship among the signals A, B, A + B and AB when a phase difference occurs in the rotational movement of the center of gravity of each vibrating portion of the sound piece B10 and the sound piece B11 due to the Coriolis force. The effect of the Coriolis force changes the relative phases of the signal A indicated by the dashed line and the signal B indicated by the broken line. Sound piece B1
The relative phases of the signal A and the signal B change substantially in proportion to the magnitude of the rotational speed ω of the center of gravity of the vibrating portion of the sound piece B11. Assuming that the phase of the signal A is advanced and the phase of the signal B is delayed by the rotation speed ω, when the rotation speed is −ω, the phase of the signal A is delayed, the phase of the signal B is advanced, and the phase change of the signals A and B is ω. Direction. On the other hand, regardless of the presence or absence of the Coriolis force, the signals A + B and AB shown by solid lines maintain the phase when the Coriolis force does not work. The Coriolis force causes a slight change in the amplitude of the signal A + B, and the signal A-B
B generates an amplitude.

FIG. 16 shows the relationship among the signals A, B, A + B and AB using vectors. In this case, the amplitude of the signal is represented by the length of the vector, and the phase is represented by the rotation of the vector. The effect of the Coriolis force can be detected as a change in the amplitude of the signals A + B and AB. It should be noted here that when the signal A and the signal B change only in phase and the amplitude does not change, the relative phase relationship between the signals A + B and AB is always 90 degrees regardless of the magnitude of the Coriolis force. Is to be kept.

In this embodiment, a lock-in amplifier is used to detect a small output Coriolis force, and only the same frequency component as the reference signal is extracted from the detected signal and integrated to obtain a high S / N ratio. Try to realize
In this case, an accurate reference signal having the same phase as the detected signal is required. First, the signals A, B, and A + B as detected signals reflecting the Coriolis force have a large output even in the absence of the Coriolis force, and thus are not suitable for capturing a change due to a small Coriolis force. On the other hand, since the signal AB does not have an output when there is no Coriolis force, it is most suitable as a detected signal in consideration of a dynamic range, and is used. On the other hand, as the reference signal, the signals A and B cannot be used because the phase changes due to the Coriolis force, and the AB signal having the most accurate phase itself has no AC output or is unstable when the Coriolis force does not work or is small. So you can't use it. However, as shown in FIG. 16, the A + B signal always has a stable large amplitude and a phase difference that is exactly 90 degrees different from the AB signal. Therefore, a signal obtained by shifting the phase of the A + B signal by 90 degrees is used as the reference signal.

As shown in FIG. 24, the signal A and the signal B are input to a subtraction circuit BG0 and input to a lock-in amplifier BP0. Further, the signal A and the signal B are input to the adder BK0, the phase is shifted by 90 degrees by the phase shifter BI0, and the binarization circuit BC0 is output.
A switching signal is generated and input to the lock-in amplifier BP0 as a reference signal. As a result, the AB signal becomes A +
The B signal is full-wave rectified at a timing shifted by 90 degrees, and is converted into a DC output. With this configuration, most signal components other than the frequency of the reference signal regarded as noise are removed, and Coriolis force detection with very good S / N can be realized.

Therefore, only the phase difference between the detecting piezoelectric element B24 of the sound piece B10 for detecting the bending vibration in the Z direction and the detecting piezoelectric element B28 of the sound piece B11 is extracted as a direct current.
Thus, the value of the angular velocity ω can be accurately known.

The sound piece B10 and the sound piece B11 in this embodiment can be operated as a vibrating gyroscope.
In this case, for example, if the phase shift amounts of the phase shift circuits BL1 and BL2 are set to 0 degree, the sound piece B10 and the sound piece B11 can be vibrated linearly. The amplitude of the center of gravity of the vibrating portion of B10 and the sound piece B11 becomes maximum at the minimum position, and does not work at the maximum amplitude position. On the other hand, in the rotary gyro according to the present embodiment, the center of gravity of the vibrating portion of the sound piece B10 and the sound piece B11 always has a maximum speed because of the rotational movement. Sound piece B10
When the center of gravity of the vibrating portion of the sound piece B11 has the same amplitude, in the case of linear vibration, only a Coriolis force approximately equal to the effective value of the AC acts as compared with the case of rotation. In other words, the rotating gyro in the present embodiment is about 1.
Coriolis force can be detected with four times higher efficiency.

Further, when exciting a vibrating gyroscope that performs natural vibration, vibration energy cannot always be applied without limit. In a vibrating gyroscope that vibrates linearly, when the vibration amplitude increases, the vibration becomes unstable due to the non-linearity of the restoring force with respect to the amplitude of the vibrating body, and it is not possible to stably continue the vibration with the large amplitude. On the other hand, in a rotary gyro, a stable rotational motion can be continued even with a large amplitude due to the centrifugal force of the rotating vibrating body. Therefore, the rotating gyro can give a large amplitude displacement to the vibrating body with respect to the vibrating gyroscope having the same shape and size.

The rotary gyro according to the present embodiment has a larger and higher Coriolis force detection efficiency for the same amplitude than, for example, the vibrating gyro using the sound piece B10 and the sound piece B11 used in the present embodiment as they are. Coriolis force can be generated. Therefore, the size can be reduced while maintaining sufficient detection sensitivity with respect to the vibrating gyroscope.

(Fourth Embodiment) Hereinafter, an embodiment of a rotary gyro according to the present invention will be described with reference to the drawings. FIGS. 1 to 12 and FIGS. 14 to 16 show a rotary gyro according to an embodiment of the present invention. FIG. 1 shows the appearance of a four-legged tuning fork type vibration gyro, hereinafter referred to as a four-forged type. FIG. 2 is a perspective view showing the position of the element, showing another position for vibration adjustment, and showing coordinates used in the following description. FIG. 2 is a sectional view of the foot, a circuit block, and FIG. 3 is a schematic diagram of wiring, FIG. 3 is a cross-sectional view of a foot viewed from the tip side of a four-pronged foot, a detailed circuit example, and a schematic wiring diagram. FIGS. FIG. 6 is a perspective view, FIG. 6 is an external view showing a configuration of a rotary gyro in which a four-forked type is enclosed in a cylindrical tube, and FIG. 7, FIG. 8, FIG. 9, FIG. 10, FIG. FIG. 14 is an operation explanatory view schematically showing a cross section of the foot as viewed from the tip end side of the mold, and FIGS. Is a waveform diagram showing a signal, Figure 16 is an operation explanatory diagram representing a vector signal from the piezoelectric element.

[Description of Structure of Rotary Gyro: FIGS.
FIGS. 3 and 6] As shown in FIG. 1, the four-forked mold 10 includes a first leg 11, a second leg 12, a third leg 13, and a fourth leg 14.
And a base 15. The leg is made of elastic metal or quartz glass, has a square pole shape, and has a drive unit and a detection unit each composed of a piezoelectric element attached to a side surface of the square pole. The base is made of metal or quartz glass having elasticity, and has a quadrangular prism shape. The first leg 11, the second leg 12, the third leg 13 and the fourth leg 14 are arranged at the four vertices of the rectangular base 15 in parallel with each other,
Base 15, first leg 11, second leg 12, third leg 13
And the fourth foot 14 is an integral structure.

The metal used in the fourth embodiment is as follows.
An alloy containing 50% of iron, 35% of nickel, and 9.1% of chromium, whose temperature dependence of the elastic modulus is very small, is called an elinvar. Similarly, when using quartz glass, which has very low temperature dependence of the elastic modulus, a thin film of conductive material such as silver or chromium is formed on a part of the surface in advance by electroless plating or vapor deposition, etc. The common electrode of the piezoelectric element is used.

In the following description of the four-forged mold 10, the coordinate axes Y, Z and X are set in directions parallel to the respective sides. At this time, the longitudinal direction, that is, the direction in which the foot is extended is the Y axis,
Let the width direction be the Z axis and the thickness direction be the X axis. The longitudinal direction, the width direction and the thickness direction of the four-forked mold 10 determined in this way are:
They are parallel to the Y axis, Z axis and X axis, respectively. However, 4
Since the fork 10 has a symmetrical shape in the XZ plane, the terms width and thickness used herein have no special meaning. In the following, the term width in the X or Z direction, or simply the width of the foot, is used.

FIG. 1 shows, by way of example, a state in which a driving section and a detecting section each composed of a piezoelectric element are adhered to the first leg 11, the second leg 12, and the third leg 13. The piezoelectric element has a thin plate shape, and an alloy such as silver or chromium is vapor-deposited on both surfaces in advance. An epoxy-based conductive adhesive is applied to one side of the piezoelectric element and attached to each foot.

FIG. 2 shows a piezoelectric element having the shape shown in FIG.
The first foot 11, the second foot 12, the third foot 13, and the fourth foot 14 are shown in a cross section taken along the X-Z plane. Piezoelectric elements 23 and 25 are attached to the first foot 11 and piezoelectric elements 27 and 29 are attached to the second foot 12 for self-oscillation. For detection, the piezoelectric element 3 is attached to the third leg 13.
3 and the piezoelectric element 37 is attached to the fourth leg 14. In addition, the third foot 1 is used for rotation status monitoring.
3, a piezoelectric element 31 is attached to the fourth leg 14, and a piezoelectric element 35 is attached to the fourth leg 14.

FIG. 2 shows the vibrating piezoelectric elements 23, 25 and 27.
Circuit 29, which is used in combination with the electrodes 29 and 29 to self-oscillate all the legs, phase shift circuits LA and LB for delaying the oscillation phase by 90 degrees and adjusting the amplitude, and a piezoelectric element 33 for detection.
Circuit K for adding the signals from the respective electrodes of
0, a phase shift circuit I0 for changing the phase of the added signal, a binarization circuit C0 for binarizing the phase-shifted signal, and subtracting a signal from each electrode of the detection piezoelectric elements 33 and 37 to obtain a reference signal. , A lock-in amplifier P0 that performs phase detection of the subtracted signal using a reference signal and converts the signal into a DC voltage, and shows wiring between them.

FIG. 3 shows an example of realizing the transmitting circuit H0 of FIG. 2 as an operational amplifier H1 forming an interference buffer, a trimmer resistor H2 and a capacitor H7 forming a low-pass filter, an operational amplifier H3 and a resistor H4 forming a inverting amplifier. H6 indicates a negative power supply D for applying a DC bias.
1 and a dividing resistor D2.

FIG. 3 shows a trimmer resistor LA1 and a capacitor LA2 as an example for realizing the phase shift circuit LA of FIG.

FIG. 3 shows a trimmer resistor LB1 and a capacitor LB2 as an example for realizing the phase shift circuit LB of FIG.

FIG. 3 shows, as an example of realizing the adder circuit K0 of FIG. 2, operational amplifiers K1 to K constituting an interference buffer.
2, resistors K3-K4.

FIG. 3 shows a resistor I1 and a capacitor I2 constituting a low-pass filter as an example for realizing the phase shift circuit I0 of FIG.

FIG. 3 shows a first comparator C1 and a second comparator C2 as an example for realizing the binarization circuit C0 of FIG.

FIG. 3 shows an example of realizing the subtraction circuit G0 of FIG. 2 by using interference buffers G1 to G2, an operational amplifier G3 and resistors G4 to G7 constituting a first differential amplifier circuit, and a second differential amplifier circuit. The operational amplifier G8 and the resistors G9 to
G12 is shown.

FIG. 3 shows an example of realizing the lock-in amplifier P0 shown in FIG.
To P7, an operational amplifier P8 constituting a second bandpass filter, capacitors P9 to P10, and resistors P11 to P1
4, a first analog switch P15, a second analog switch P16, a resistor P17 forming a low-pass filter
And a capacitor P18.

[Description of operation and action of vibrating gyroscope: FIG.
3, 4, 5, 5, 7, 8, 9, 10, 1
1, FIG. 12, FIG. 14, FIG. 15 and FIG. 16] FIG. 4 and FIG.
The operation of the piezoelectric element is shown in FIG. PZT used in this embodiment
When a piezoelectric element called a piezoelectric element is polarized by applying a high voltage in advance, the direction of distortion differs depending on the direction of the voltage applied to the piezoelectric element. The (+) plane 58 shown in FIG. 4 is a plane to which a positive voltage has been applied to the back surface during polarization.
When a high potential is applied to the back surface, the thickness increases and the length and width shrink. FIG. 5 shows a (−) surface 59 which is a back surface of the surface 58. When a positive voltage is applied to the (-) surface 59, the thickness of the (-) surface 59 is reduced, and the length and width are increased. The symbols (+) or (-) written in FIG. 2 and FIG. 3 indicate which of the surfaces of the piezoelectric element adhered to each foot of the four-way mold 10 is the surface adhered to the foot. Is shown. FIG.
In FIG. 3, the first neutral line 39 of the bending vibration of the first foot 11 in the Y direction is indicated by a dot, and the second neutral line 40 of the bending vibration of the second foot 12 in the Y direction is indicated by a point. , The third neutral line 41 of the bending vibration of the third leg 13 in the Y direction is indicated by a dot, and the fourth neutral line 42 of the bending vibration of the fourth leg 14 in the Y direction is indicated by a point. The lines outside the drawing schematically show the wiring between the electrodes of each piezoelectric element.

It has been pointed out that the polarization state of PZT may be degraded when a voltage is applied in the direction opposite to the polarization direction. In the present embodiment, the driving is performed at a voltage that can be ignored compared to the high voltage applied at the time of forming the polarization, so there is no particular problem. FIG. 3 shows a method for dealing with this point. Piezoelectric elements 25, 27, 29, 35, 23, 31, 3
The electrode portions 3 and 37 are usually grounded to the ground as shown in FIG. 2 since the base of the four-pronged mold 10 forms a common electrode in a conductor such as an elinver.
In order to always apply a voltage in the same direction as the voltage applied at the time of polarization as a measure against polarization deterioration, it is connected to a voltage source D1 at a level lower than ground. Further, in order to adjust the magnitude of the DC bias, the DC bias is connected via a division resistor D2.

In FIG. 2, the piezoelectric element 3 of the third leg 13
When a voltage is applied to the electrode of the piezoelectric element 25 of the first foot 11 from the oscillation circuit H0 which refers to the voltage obtained by adding the voltage from the piezoelectric element 37 of the third and fourth feet 14 by the adding circuit K0, For example, the piezoelectric element 25 contracts in the Y direction, and as a result, bending displacement occurs in the X axis direction. Over time, this direction changes, so that the first foot 11
Bending vibration occurs in the axial direction. At the same time, with reference to the voltage obtained by adding the voltage from the piezoelectric element 33 of the third leg 13 and the piezoelectric element 37 of the fourth leg 14 by the adding circuit K0, the oscillation circuit in which the output voltage is delayed by 90 degrees by the phase shift circuit LA. From H0, the first
When a voltage is applied to the electrode of the piezoelectric element 28 of the foot 11
For example, the piezoelectric element 28 contracts in the Y direction, and as a result, bending displacement occurs in the Z axis direction. This direction changes over time, and as a result, the first foot 11 bends and vibrates in the Z-axis direction. At this time, the first foot 11 makes a clockwise rotation.

In FIG. 2, the piezoelectric element 3 of the third leg 13
When a voltage is applied to the electrode of the piezoelectric element 29 of the second foot 12 from the oscillation circuit H0 that refers to the voltage obtained by adding the voltage from the piezoelectric element 37 of the third and fourth feet 14 by the adding circuit K0, For example, the piezoelectric element 29 contracts in the Y direction, and as a result, bending displacement occurs in the X axis direction. This direction changes over time, and as a result, the second foot 12 bends and vibrates in the X-axis direction. At the same time, the piezoelectric element 33 of the third leg 13
With reference to the voltage obtained by adding the voltage from the piezoelectric element 37 of the fourth leg 14 by the adder circuit K0, the oscillation circuit H0 in which the output voltage is delayed by 90 degrees by the phase shift circuit LB, the second leg 1
When a voltage is applied to the electrodes of the second piezoelectric element 27, for example, the piezoelectric element 27 contracts in the Y direction, and as a result, bending displacement occurs in the Z axis direction. Over time, this direction changes, and as a result, the second leg 12 bends and vibrates in the Z-axis direction. At this time, the second foot 12 performs a counterclockwise rotation.

At this time, even if only the first foot 11 and the second foot 12 are driven, the vibrations of the first foot 11 and the second foot 12 are transmitted through the base 15, and Of the first leg 1 and the fourth leg 14 are automatically excited.
A first rotation which is a cooperative operation of the four-forked mold 10 as a whole, in which the first and fourth legs 14 rotate clockwise and the second leg 12 and the third leg 13 rotate counterclockwise. Movement self-oscillates. At this time, the first foot 11 and the fourth foot 14 are performed. The clockwise rotations have 180 degrees different rotation phases from each other, and the counterclockwise rotations performed by the second foot 12 and the third foot 13 have 180 degrees different rotation phases.
The rotational movements of the book's feet balance each other and the base does not vibrate at all.

The mechanism for causing the first rotary motion to self-oscillate in the four-way mold 10 will be described in more detail. 4
From the four legs of the fork 10, for example, using the oscillation circuit H <b> 0 with reference to the voltage of the piezoelectric element 29 of the second leg 12,
When a voltage is applied to the piezoelectric element 25 of the foot 11 and vibrated in the X direction, the displacement direction of each foot of the four-way mold 10 at a certain moment in FIG. A first bending vibration occurs in which the foot 11 and the second foot 12 swing in a tuning fork shape, and the third foot 13 and the fourth foot 14 swing in a tuning fork shape in opposite phases. In the four-branch mold 10, this oscillation mode is the most stable, and in most cases, it oscillates in this mode unless a filter for limiting the oscillation frequency is provided. When a voltage is applied to the piezoelectric element 23 of the first foot 11 using the oscillation circuit H0 with reference to the voltage of the piezoelectric element 31 of the third foot 13 and vibrated in the Z direction, a four-pronged shape is shown in FIG. The direction of displacement of each of the legs 10 at a certain moment is schematically indicated by an arrow, so that the first leg 11
And the third leg 13 swings in a tuning fork shape, and the second bending vibration occurs in which the second leg 12 and the fourth leg 14 swing in a tuning fork shape in opposite phases. In the four-pronged mold 10, this oscillation mode is also the most stable, and in most cases, it oscillates in this mode unless a filter or the like for limiting the oscillation frequency is provided.

On the other hand, from among the four legs of the fork 10, for example, by using the oscillation circuit H 0 with reference to the voltage of the piezoelectric element 29 of the second leg 12, Third
When a voltage is applied to the piezoelectric element 33 of the foot 13 and is simultaneously vibrated in the X direction, as shown by arrows in FIG. Feet 11
Then, the third leg 13 and the fourth leg 14 swing in the tuning fork shape in the same phase, and the third bending vibration occurs in which the third leg 13 and the fourth leg 14 swing in the tuning fork shape. Further, the oscillation element H0 is used to refer to the voltage of the piezoelectric element 31 of the third leg 13 to use the piezoelectric element 23 of the second leg 12 as a reference.
When a voltage is applied to the piezoelectric element 37 of the second foot 12 and simultaneously vibrated in the X direction, the direction of displacement of each foot of the four-forked mold 10 at a certain moment in FIG. A fourth bending vibration occurs in which the first leg 11 and the third leg 13 swing in a tuning fork shape, and the second leg 12 and the fourth foot 14 swing in the same phase in a tuning fork shape.

In the mechanism shown in FIG. 2, each leg is rotated by delaying the phase of the bending vibration in the Z direction by 90 degrees with respect to the bending vibration in the X direction. FIG.
Is generated by delaying the phase of the fourth bending vibration oscillating in the Z direction shown in FIG. 10 by 90 degrees with respect to the third bending vibration oscillating in the X direction shown in FIG. 9 and combining the two. FIG. 2 schematically shows a first rotational motion of the first rotation. In the first rotational movement shown in this embodiment, the first legs 11,
XZ of the second foot 12, the third foot 13, and the fourth foot 14
The center of gravity in the cross section makes a rotary motion, but the first foot 11 and the fourth foot 14 make a clockwise rotary motion, and the second foot 1
The second and third legs 13 make a counterclockwise rotation. Here, the displacement direction at a certain moment is indicated by an arrow. On the other hand, FIG.
2, the phase of the fourth bending vibration oscillating in the Z direction shown in FIG. 10 is delayed by 90 degrees with respect to the first bending vibration oscillating in the X direction shown in FIG. 2 schematically shows a second rotational movement generated by the following. In the second rotational movement shown in this embodiment, the first leg 1
1, X of second foot 12, third foot 13, and fourth foot 14
The center of gravity in the -Z section makes a rotational movement, but the first foot 1
The first and third feet 13 make a clockwise rotation, and the second and fourth feet 12 and 14 make a counterclockwise rotation. Here, the displacement direction at a certain moment is indicated by an arrow.

In the circuit shown in FIG. 2, the first leg 1
Since the in-phase voltage is input to the first piezoelectric element 23 and the piezoelectric element 27 of the second foot 12, the bending vibration in the Z direction always becomes the fourth bending vibration shown in FIG. Is
Since the vibration phase of each leg is not limited, which of the first bending vibration shown in FIG. 7 and the third bending vibration shown in FIG. 9 is generated is determined on a circuit. Not. Therefore, in the circuit shown in FIG. 2, it is not determined whether the first rotational movement shown in FIG. 11 occurs or the second rotational movement shown in FIG. 12 occurs.

However, if the four-way mold 10 is formed with good symmetry, the resonance frequencies of the third bending vibration shown in FIG. 9 and the fourth bending vibration shown in FIG. Since it has a frequency clearly lower than the resonance frequency of the first bending vibration shown in FIG. 7 and the second bending vibration shown in FIG. 8 which are equal to each other, in FIG. When the fourth bending vibration is generated, the third bending vibration shown in FIG. 9 always occurs as the X-direction bending vibration oscillated by the signal of the same oscillation circuit H0. Therefore, the four-pronged mold 1
When 0 is manufactured with good symmetry, in the circuit configuration of FIG. 2, the first leg 11 and the fourth leg 14 always rotate clockwise, and the second leg 12 and the third leg A first rotational movement occurs, in which the foot 13 performs a counterclockwise rotational movement.

Each of the first bending vibration shown in FIG. 7, the second bending vibration shown in FIG. 8, the third bending vibration shown in FIG. 9, and the fourth bending vibration shown in FIG. By confirming the operation of the prototype of the four-pronged mold 10, the existence of a resonance frequency as an elastic body has been confirmed. These vibrations are balanced by the four legs, and the base 15 is a vibration node. Therefore, if the four-way mold 10 supports the bottom surface, the vibration state hardly changes depending on the supporting method. Also, the first rotational motion synthesized from the third bending vibration shown in FIG. 9 and the fourth bending vibration shown in FIG. 10, and the first bending vibration shown in FIG. 7 and FIG. In the second rotational movement synthesized from the fourth bending vibration, the four legs balance each other, and the base 15 is a vibration node and hardly vibrates. In this case, the vibration state hardly changes depending on the supporting method.

When the first rotational movement shown in FIG. 11 is occurring, the third foot 13 rotates counterclockwise and the fourth foot 14 rotates.
Rotates clockwise, but when the entire fork 10 rotates around the Y axis at a rotation speed ω, the center of gravity of the rotating third foot 13 in the XZ section and the rotating fourth foot 14 The center of gravity of the XZ section of FIG. 1 receives a Coriolis force in a direction orthogonal to the direction of displacement, but in the case of a circular motion, the third foot 13 and the fourth
The trajectory of the center of gravity of the third foot 13 and the fourth foot 14 in the XZ section does not change even from the coordinate system rotating at the rotation speed ω to which the foot 14 belongs. In other words, the Coriolis force acting on the center of gravity of the XZ cross section of the third foot 13 and the fourth foot 14 that draw a circular orbit shown in FIG. Therefore, the rotation frequency f of the center of gravity of the XZ cross section of the third foot 13 and the fourth foot 14 that draw a circular orbit is the same as that of the XZ cross section of the third foot 13 and the fourth foot 14. Because the rotation of the center of gravity keeps inertia with respect to the stationary system,
Even if it changes by ω in the coordinate system rotating at the rotation speed ω to which the third foot 13 and the fourth foot 14 belong, the amplitude of the center of gravity of the XZ section of the third foot 13 and the fourth foot 14 is It does not change.
That is, when the rotation of the center of gravity of the XZ section of the third foot 13 and the fourth foot 14 is occurring, the third foot 13 and the fourth foot 14 are rotated.
The effect of rotating the entire fork 10 including the first leg 14 at the rotation speed ω around the Y axis is the effect of the third leg 13 and the fourth leg 13.
Detecting piezoelectric elements 33 and 3 attached to the feet 14
7, the frequency f of the drive signal generated by the oscillation circuit H0 is
, The change in the frequency of the rotating third foot 13 and the rotating fourth foot 14 with respect to | ω |. However,
When the rotation speed ω is counterclockwise rotation, the frequency of rotation of the center of gravity of the XZ cross section of the third foot 13 that rotates counterclockwise decreases, and the fourth foot 14 that rotates clockwise. The rotation frequency of the center of gravity of the XZ section becomes larger.

However, the four-pronged type 10 has an oscillation circuit H
Using 0, the first rotational motion is self-oscillated at the oscillation frequency f in the X and Z directions. Accordingly, the rotational frequency of the rotational motion of each of the centers of gravity of the XZ cross section of the third leg 13 and the fourth leg 14 is also returned to f when Coriolis force does not act. This restoring force is caused by the rotation speed ω of the entire fork 10, the phase lag of the detecting piezoelectric element 33 reflecting the rotation of the center of gravity of the X-Z section of the third foot 13, and the X-force of the fourth foot 14. -Z
The phase difference between the detecting piezoelectric elements 33 and 37 caused by the phase advance of the detecting piezoelectric element 37 that reflects the rotational movement of the center of gravity of the cross section works to the extent that it is substantially proportional. Therefore, by measuring the phase difference between the detecting piezoelectric elements 33 and 37 instead of the slight frequency change, the rotational speed ω of the entire four-forked mold 10 is measured.
You can know.

The rotational frequency of the rotational movement of each of the centers of gravity of the XZ cross section of the third leg 13 and the fourth leg 14 is also returned to f when Coriolis force does not act.
And the rotational speed of each rotational movement of the center of gravity of the XZ cross section of the fourth leg 14 changes by the rotational angular velocity ω of the entire four-forked mold 10 as viewed from the stationary system, and as a result, the third 13 X- The center of gravity of the Z section is rotated at the rotational angular velocity-| Ω-ω |, and the center of gravity of the XZ section of the fourth foot 14 is the rotational speed Ω + ω.
Will rotate. Therefore, in an equilibrium state in which a phase shift has occurred due to the rotation speed ω of the entire fork 10, the third
The trajectory of the rotational movement of the center of gravity of the XZ section of the foot 13 and the fourth foot 14 slightly changes due to a change in centrifugal force.
At this time, the radius of rotation of the center of gravity of the third foot 13 in the XZ section increases, and the radius of rotation of the center of gravity of the fourth foot 14 in the XZ section decreases. To detect the Coriolis force, the bending vibration of the third foot 13 and the fourth foot 14 in the X or Z direction
The relative change in each amplitude can also be used, but the change in amplitude is small. In the present embodiment, a method for measuring a phase difference using signals from the piezoelectric elements 33 and 37 will be described.

In FIG. 2, the output from the electrode portion of the piezoelectric element 33 for detecting the vibration of the third leg 13 in the X direction is a signal B, and the piezoelectric element 3 for detecting the vibration of the fourth leg 14 in the X direction.
The output from the electrode unit 7 is signal A. The first rotational movement has a third bending vibration as a component in the X direction. In the third foot 13 rotating counterclockwise, the voltage output B from the detecting piezoelectric element 33 of the third foot 13 reflecting the third bending vibration is determined by the counterclockwise rotation ω of the four-forked mold 10. When Coriolis force acts, the phase is delayed. On the other hand, in the fourth foot 14 that rotates clockwise, the voltage output A from the detecting piezoelectric element 37 of the fourth foot 14 that reflects the third bending vibration.
When the Coriolis force is exerted by the counterclockwise rotation ω of the four-way mold 10, the phase advances. In the present embodiment, the signal A
And a signal B are input to an addition circuit K0 and a subtraction circuit G0 to generate a sum signal A + B and a difference signal AB of the signal A and the signal B, and utilize these signals.

FIG. 14 shows the relationship among the signals A, B, A + B and AB when the Coriolis force does not work. In this case, the signal A and the signal B are the third flexural vibrations, respectively, and these are completely matched signals by adjusting the amplitude and phase by the low-pass filters LA and LB shown in FIG. Signal A + B is a signal having twice the amplitude of signals A and B, and signal AB has no amplitude.

FIG. 15 shows the relationship among the signals A, B, A + B and AB when there is a phase difference between the rotational movements of the third leg 13 and the fourth leg 14 due to the Coriolis force. The effect of the Coriolis force changes the relative phases of signal A and signal B. The relative phases of the signal A and the signal B change substantially in proportion to the rotation speed ω of the entire four-way mold 10. 4
The phase of the signal A advances due to the rotation speed ω of the entire fork 10,
If the phase of the signal B is delayed, the phase of the signal B is advanced at the rotation speed −ω of the entire fork 10, the phase of the signal A is delayed, and the change in the phase of the signals A and B depends on the rotation direction of the rotation speed ω. become. On the other hand, signal A regardless of the presence or absence of Coriolis force
+ B and AB maintain the phase when Coriolis force does not work. The Coriolis force causes a slight change in the amplitude of the signal A + B, and generates an amplitude in the signal AB.

FIG. 16 shows the relationship between the signals A, B, A + B, and AB using vectors. In this case, the amplitude of the signal is represented by the length of the vector, and the phase is represented by the rotation of the vector. The effect of the Coriolis force can be detected as a change in the amplitude of the signals A + B and AB. It should be noted here that when the signal A and the signal B change only in phase and the amplitude does not change, the relative phase relationship between the signals A + B and AB is always 90 degrees regardless of the magnitude of the Coriolis force. Is to be kept.

In this embodiment, a lock-in amplifier is used to detect a small output Coriolis force, and only the same frequency component as that of the reference signal is extracted from the detected signal and integrated to obtain a high S / N ratio. Try to realize
In this case, an accurate reference signal having the same phase as the detected signal is required. First, the signals A, B, and A + B as detected signals reflecting the Coriolis force have a large output even in the absence of the Coriolis force, and thus are not suitable for capturing a change due to a small Coriolis force. On the other hand, since the signal AB does not have an output when there is no Coriolis force, it is most suitable as a detected signal in consideration of a dynamic range, and is used. On the other hand, as the reference signal, the signals A and B cannot be used because the phase changes due to the Coriolis force, and the AB signal having the most accurate phase itself has no AC output or is unstable when the Coriolis force does not work or is small. So you can't use it. However, as shown in FIG. 16, the A + B signal always has a stable large amplitude and a phase difference that is exactly 90 degrees different from the AB signal. Therefore, a signal obtained by shifting the phase of the A + B signal by 90 degrees is used as the reference signal.

As shown in FIG. 2, the signal A and the signal B are inputted to the subtraction circuit G0, and the high common-mode rejection ratio CMRR shown in FIG.
The signal A-B and the signal B-A having the opposite phase to the signal A-B are generated by the differential amplifier circuits G1 to G12 having the configuration described above and input to the lock-in amplifier P0 shown in FIG. As shown in FIG. 3, inside the lock-in amplifier P0, band-pass filters P1 to P14 are used to remove the DC component and odd-order harmonic components of the signal AB and the signal BA having the opposite phase to the signal AB. Switching is performed using analog switches P15 to P16, and is converted to DC using smoothing and integrating circuits P17 to P18. Also, as shown in FIG. 2, the signal A and the signal B are input to the adder circuit K0, the phase is shifted by 90 degrees by the phase shift circuits I0 to I1 shown in FIG. Is generated and input to the analog switches P15 to P16. As a result, the AB signal is subjected to full-wave rectification at a timing obtained by shifting the A + B signal by 90 degrees, and is converted into a DC output. Here, a switching method was used instead of a multiplier for phase detection because of dislike of DC drift. In this configuration, most of the signal components other than the frequency of the reference signal, which is regarded as noise, are removed.
/ N can be detected with good Coriolis force.

Therefore, only the phase difference between the detecting piezoelectric element 33 of the third foot 13 and the detecting piezoelectric element 37 of the fourth foot 14 for detecting the third bending vibration is extracted as a direct current. As a result, the value of the rotation speed ω of the entire fork 10 can be accurately known.

The third bending vibration of the four-way mold 10 according to the present invention constitutes a tuning fork type oscillator having a large Q value.
That is, it has a very stable frequency. Therefore, by using this as a reference signal, the width of frequency extraction, which is a function of the lock-in amplifier, can be extremely reduced. In other words, in the configuration of the present embodiment, noise other than the signal caused by the angular velocity ω can be almost excluded, and the S / N is very good.

[0138] The four-way mold 10 in the present embodiment can also be operated as a vibrating gyroscope. In this case, for example, if the phase shift amount of the phase shift circuit LA is 0 degree and the phase shift amount of the phase shift circuit LB is 180 degrees, the four-way mold 10 can be vibrated linearly, but the Coriolis force is proportional to the speed. Therefore, at the position where the amplitude is the minimum, it becomes maximum, and at the position where the amplitude is the maximum, it does not work at all. On the other hand, in the rotary gyro according to the present embodiment, since the four-way mold 10 performs a rotary motion, it always has the maximum speed. When the four-pronged mold 10 has the same amplitude, in the case of linear vibration, only a Coriolis force equivalent to the effective value of the alternating current acts as compared with the case of rotation. In other words, the rotating gyro in the present embodiment can detect the Coriolis force with an efficiency about 1.4 times higher than that of the vibrating gyro.

Further, when exciting a vibrating gyroscope that performs natural vibration, vibration energy cannot be applied without limit. In a vibrating gyroscope that vibrates linearly, when the vibration amplitude increases, the vibration becomes unstable due to the non-linearity of the restoring force with respect to the amplitude of the vibrating body, and it is not possible to stably continue the vibration with the large amplitude. On the other hand, in a rotary gyro, a stable rotational motion can be continued even with a large amplitude due to the centrifugal force of the rotating vibrating body. Therefore, the rotating gyro can give a large amplitude displacement to the vibrating body with respect to the vibrating gyroscope having the same shape and size.

The rotary gyro according to the present embodiment has a higher Coriolis force detection efficiency for the same amplitude and a larger Coriolis force than, for example, the vibrating gyro using the four-way mold 10 used in the present embodiment as it is. Can be generated. Therefore, the size can be reduced while maintaining sufficient detection sensitivity with respect to the vibrating gyroscope.

[0141]

As is apparent from the above description, the rotary gyro according to the present invention is different from a vibrating gyro having the same size.
The detection efficiency of the Coriolis force is large, and a large Coriolis force can be generated. Therefore, the rotating gyroscope of the present invention can be downsized while maintaining sufficient detection sensitivity with respect to the vibration gyroscope of the same size.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a four-leg tuning fork type rotary gyro according to an embodiment of the present invention, showing the position of a piezoelectric element, showing another position for adjusting vibration, and showing coordinates used in the following description. FIG.

FIG. 2 is a schematic cross-sectional view of a foot, a circuit block, and a wiring of the four-legged tuning fork type rotary gyro according to the embodiment of the present invention, as viewed from the tip end of the foot.

FIG. 3 is a cross-sectional view of a foot, a detailed circuit example, and a schematic wiring diagram of the four-legged tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 4 is a perspective view of a piezoelectric element used in a rotary gyro according to an embodiment of the present invention.

FIG. 5 is a perspective view of a piezoelectric element used in a rotary gyro according to an embodiment of the present invention.

FIG. 6 is an external view showing a configuration of a gyro element sealed in a cylindrical tube of a four-leg tuning fork type rotary gyro according to an embodiment of the present invention.

FIG. 7 is an operation explanatory diagram schematically showing a cross section of the foot of the four-leg tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 8 is an operation explanatory view schematically showing a cross section of the foot of the four-legged tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 9 is an operation explanatory view schematically showing a cross section of the foot of the four-legged tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 10 is an operation explanatory view schematically showing a cross section of the foot of the four-leg tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 11 is an operation explanatory view schematically showing a cross section of the foot of the four-legged tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 12 is an operation explanatory view schematically showing a cross section of the foot of the four-leg tuning fork type rotary gyro according to the embodiment of the present invention as viewed from the tip end side of the foot.

FIG. 13 is a perspective view showing a conventional resonator element vibrating gyroscope.

FIG. 14 is a waveform chart showing a detection signal of a rotating gyro according to an embodiment of the present invention.

FIG. 15 is a waveform diagram showing a detection signal of a rotating gyro according to an embodiment of the present invention.

FIG. 16 is an operation explanatory diagram showing a detection signal of the rotating gyro according to the embodiment of the present invention as a vector.

FIG. 17 is a top view of a motor and a circuit block diagram showing a configuration of a rotary gyro according to an embodiment of the present invention.

FIG. 18 is a waveform chart showing a detection signal of a rotating gyro according to an embodiment of the present invention.

FIG. 19 is a perspective view showing an external appearance of a resonating type rotary gyro according to an embodiment of the present invention, showing a piezoelectric element and a support portion, and showing coordinates used for description.

FIG. 20 is a front view of a film used for supporting a sound piece type rotary gyro according to an embodiment of the present invention.

FIG. 21 is a schematic cross-sectional view, a circuit block, and a wiring diagram of the sound piece of the sound piece type rotary gyro according to the embodiment of the present invention, as seen from the tip side of the sound piece.

FIG. 22 is an operation explanatory diagram schematically showing a cross section of a vibration antinode of the sound piece viewed from the tip side of the sound piece of the sound piece type rotary gyro according to the embodiment of the present invention.

FIG. 23 is an operation explanatory diagram schematically showing a cross section of a vibration antinode of the sound piece viewed from the tip side of the sound piece of the sound piece type rotary gyro according to the embodiment of the present invention.

FIG. 24 is a schematic cross-sectional view, a circuit block, and a wiring diagram of a sound piece of a sound piece type rotary gyro according to an embodiment of the present invention, as viewed from the tip side of the sound piece.

[Explanation of symbols]

10 Four-legged tuning fork type vibrating gyroscope 11, 12, 13, 14 Four-legged tuning fork foot 15 Four-legged tuning fork base 16 Base 17 Metal cap 18, 19, 20, 21 Lead wire 22 Wiring board 23, 25, 27 , 29, 31, 33, 35 and 37
Piezoelectric elements 39 to 42 Neutral lines A and B of bending vibration A, B Voltage waveform D1 Negative power supply D2 Dividing resistance H0 Oscillation circuit H1 Operational amplifier H2 Adjusting resistance H3 Operational amplifier H4 to H6 Resistance H7 Capacitor LA Low-pass filter LA1 Trimmer resistance LA2 Capacitor LB Low-pass filter LB1 Trimmer resistor LB2 Capacitor K0 Addition circuit K1 to K2 Operational amplifier K3 to K4 Resistance I0 Phase shift circuit I1 Resistance I2 Capacitor C0 Binarization circuit C1 First comparator C2 Second comparator G0 Subtraction circuit G1 to G2 Interference buffer G3 Operational amplifier G4 to G7 resistance G8 operational amplifier G9-G12 resistance P0 lock-in amplifier P1 operational amplifier P2-P3 capacitor P4-P7 resistance P8 operational amplifier P9-P10 capacitor P11-P14 resistance P15 1 analog switch P16 second analog switch P17 resistor P18 capacitor 58 (+) surface 59 (-) surface 71 vibrator 76 drive detection piezoelectric element 77 drive detection piezoelectric element MB housing MD1 drive circuit MD2 detection circuit MR1 first 1 rotor MJ1 first rotor rotation axis MS1 first stator ME1 first encoder MT1 magnet MR2 second rotor MJ2 second rotor rotation axis MS2 second stator ME2 second encoder MT2 magnet B10 sound Piece B11 Sound piece B12 Support position B13 Support position B14 Support section B14W Support section frame B14M Support section film B14H Support section hole B15 Support section B15W Support section frame B15M Support section film B15H Support section hole B21 to B24 Piezoelectric Element B25 to B28 Piezoelectric element BHC0 oscillation circuit BH0 oscillation circuit BL phase shift circuit BL1 phase shift circuit BL2 phase shift circuit BK0 adder circuit BI0 phase shift circuit BC0 binarization circuit BG0 subtraction circuit BP0 lock-in amplifier

Claims (10)

[Claims] 1. A rotating system comprising: two rotating units for rotating at the same constant speed in opposite directions as viewed from a stationary system; and a rotation system for rotating the two rotating units viewed from the coordinate system in a coordinate system for measuring the rotating speed. A rotary gyro having means for detecting a speed difference. 2. A coordinate system for measuring rotation speed, comprising two rotating units for performing rotations converging to the same constant speed within a certain time in opposite directions when viewed from a coordinate system for measuring rotation speed. And a means for detecting a rotational phase difference between the two rotating parts. 3. The rotary gyro according to claim 2, wherein the rotating part is a rotor made of a permanent magnet, the driving part is a stator made of an electromagnet, and the detecting part is an encoder made of an electromagnet. And a rotating gyro. 4. The rotary gyro according to claim 2, wherein the rotating portion is a center of gravity of each of the vibrating portions of the vibrating member supporting the node of the vibration, and vibrates the vibrating member from two directions. A rotary gyro comprising: vibrating means; and detecting means for detecting vibration from one direction. 5. The rotary gyro according to claim 4, wherein the vibrating body is a sound piece supporting a node of vibration. 6. The rotary gyro according to claim 4, wherein the vibrating body is a four-leg tuning fork supporting a node of vibration. 7. The rotary gyro according to claim 4, wherein the foot is made of a material having elasticity, the foot is a quadrangular prism, and the foot has a driving unit and a detecting unit on a side surface of the quadrangular prism. The drive unit and the detection unit are made of piezoelectric elements, the base is made of an elastic material, the base is a quadrangular prism, the base and four feet are integrated, and the four feet are parallel to each other The bottom of the base is used for support, and self-oscillation is performed using the piezoelectric elements of the first and second feet, and the first and second feet are arranged at the base. At the same time as performing the first bending vibration that swings in phase with each other, the first bending vibration is performed using the piezoelectric elements of the first and second feet, and the first bending vibration is performed in a direction orthogonal to the first bending vibration. A second flexural vibration in which the vibration and the frequency coincide, the phases differ by 90 degrees, and the first foot and the second foot swing in phase with each other. Is generated, and as a combined vibration of the first bending vibration and the second bending vibration, the center of gravity of the cross section in the direction in which the foot of the first foot extends and the cross section in the direction in which the foot of the second foot extends are obtained. Generates a first rotational motion, which is a rotational motion that rotates in opposite directions, the frequency of the first or second flexural vibration caused by the Coriolis force due to the rotation of the base. A rotating gyro, wherein a change is detected by a detection unit of a third foot rotating in the same direction as the first foot and a fourth foot rotating in the same direction as the second foot. 8. The rotary gyro according to claim 7, wherein the phase-changed first bending vibration generates a voltage output generated by a piezoelectric element attached to the third foot and a phase change. A first bending vibration includes an addition circuit that adds a voltage output generated by the piezoelectric element attached to the fourth foot;
A phase shift circuit that shifts the output of the adder circuit by 90 degrees; and a binarization circuit that binarizes the output of the phase shift circuit. A subtraction circuit for subtracting a voltage output generated by the attached piezoelectric element and a voltage output generated by the piezoelectric element attached to the fourth leg by the first bending vibration having a changed phase; A rotary gyro comprising a lock-in amplifier for detecting an output using an output of the binarization circuit. 9. The rotary gyro according to claim 8, further comprising: an amplitude / phase adjusting circuit for adjusting an output signal of the oscillation circuit so that a trajectory of the first rotational motion is substantially a circular trajectory. It is characterized by the following. 10. A coordinate system for measuring a rotation speed,
It is provided with a rotating unit for performing rotation converging to the same constant speed within a certain time, and having a means for detecting a rotation drive signal and a phase difference between the rotation of the rotating unit in a coordinate system for measuring the rotation speed. A rotating gyro, wherein the rotating part is a center of gravity of each of the vibrating parts of the vibrating body that supports the node of vibration, and includes vibrating means for vibrating the vibrating body from two directions, from one direction A rotary gyro comprising a detecting means for detecting vibration.