JP3751745B2 - Vibrator, vibratory gyroscope and measuring method of rotational angular velocity - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibrator used in an angular velocity sensor used for detecting a rotational angular velocity in a rotating system, a vibratory gyroscope, and a rotational angular velocity measuring method.
[0002]
[Prior art]
Conventionally, as an angular velocity sensor for detecting a rotational angular velocity in a rotating system, a vibratory gyroscope using a piezoelectric body has been used for confirming the position of an aircraft, a ship, a space satellite, or the like. Recently, it is used as a consumer field for car navigation, detection of camera shake of a VTR or a still camera, and the like.
[0003]
Such a piezoelectric vibrating gyroscope utilizes the fact that when an angular velocity is applied to a vibrating object, a Coriolis force is generated in a direction perpendicular to the vibration. The principle is analyzed by a mechanical model (for example, “Acoustic wave device technology handbook”, Ohm, pages 491 to 497). Various piezoelectric vibratory gyroscopes have been proposed so far. For example, Sperry tuning fork type gyroscope, Watson tuning fork type gyroscope, equilateral triangular prism type piece gyroscope, cylindrical type piece gyroscope, etc. are known.
[0004]
[Problems to be solved by the invention]
However, in the conventional vibrator, the sensitivity is not necessarily high. In addition, the detection vibration is included in various noises generated along with the drive vibration, and it is difficult to accurately separate the contribution of the amplitude of the detection vibration from the detection signal. Low and signal / noise ratio was low.
[0005]
An object of the present invention is to provide a vibrator and a vibrating gyroscope that can be used to detect the rotational angular velocity of a rotating system according to a new principle.
[0006]
[Means for Solving the Problems]
  The present invention provides (1)A vibrator extending in a predetermined plane, the vibrator having a frame portion, a hollow portion is formed inside the frame portion, and each of the drive vibration systems is supported to protrude from the frame portion to the hollow portion. And two bending vibration pieces extending in a direction orthogonal to the support portion from the distal end side of the support portion, and provided at positions that are symmetrical with each other about the center of gravity of the vibrator. Each of the two drive vibration systems that flexurally vibrate in the predetermined plane and the four detection vibration pieces projecting from the frame portion to the hollow portion, and two pairs of detection vibration pieces are included. Each of which includes four detection vibration systems provided at positions symmetrical with each other about the center of gravity of the vibrator, or (2) a vibrator extending in a predetermined plane, ,  The vibrator includes a base, and each of the drive vibration systems includes a support part protruding from the peripheral part of the base part, and two bending vibration pieces extending in a direction perpendicular to the support part from the distal end side of the support part. 4 of the four driving vibration systems, each of which is provided at a position twice symmetrical about the center of gravity of the vibrator, and flexibly vibrates within the predetermined plane 4 Each of the four drive vibration systems and the detection vibration system is provided between the four drive vibration systems, and includes four detection vibration pieces protruding from the peripheral edge of the base, and each of the two pairs of detection vibration pieces is Or (4) a vibrator extending in a predetermined plane, wherein the vibration is provided with four detection vibration systems provided at positions symmetrical with each other about the center of gravity of the vibrator. The child has a base and the drive vibration system 2 drive vibration systems each including a support portion protruding from the peripheral edge of the base portion and two bending vibration pieces extending in a direction perpendicular to the support portion from the distal end side of the support portion, and the center of gravity of the vibrator The two drive vibration systems that bend and vibrate in the predetermined plane and the first detection vibration system are perpendicular to the support portion of each drive vibration system. It consists of four detection vibration pieces projecting from the peripheral edge of the base portion in the direction, and each of the two pairs of detection vibration pieces is provided at a two-fold symmetrical position around the center of gravity of the vibrator. Each of the four first detection vibration systems and the second detection vibration system is perpendicular to the support portion of each drive vibration system between the two detection vibration systems that form a pair of the four detection vibration systems. It consists of two detection vibration pieces provided in different directions. Or (2) a vibrator extending on a predetermined plane, wherein the vibration is provided with two detection vibration systems provided at positions that are symmetrical twice with respect to the center of gravity of the vibrator. Each of the driving vibration systems includes a support portion that protrudes from a peripheral edge portion of the base portion, and a flexural vibration piece that extends in a direction perpendicular to the support portion from the distal end side of the support portion. Each of the two pairs of drive vibration systems is provided at two symmetrical positions with respect to the center of gravity of the vibrator, and four drive vibration systems that flexibly vibrate in the predetermined plane. Each of the first detection vibration systems includes four detection vibration pieces projecting from the peripheral edge of the base portion in a direction perpendicular to the support portions of one pair of drive vibration systems, Each detection piece is centered on the center of gravity of the vibrator. The four detection vibration systems and the second detection vibration systems, which are provided at positions that are symmetric with each other as the second detection vibration system, in the direction perpendicular to the support portion of the other pair of drive vibration systems, Four detection vibration pieces each of which is provided at a position twice symmetrical with respect to the center of gravity of the vibrator. It is characterized by having.
[0007]
The present invention also provides a vibratory gyroscope for detecting a rotational angular velocity of a rotational component centered on a rotational axis extending in parallel with a predetermined plane, comprising the vibrator, and comprising a first vibration system And a second vibration system, and a detection means provided on the other of the first vibration system and the second vibration system.
[0008]
The present invention is also a method for detecting a rotational angular velocity of a rotational component centered on a rotational axis extending in parallel to a predetermined plane, wherein the vibrator is used, and the first vibration system and the second vibration system Driving vibration is excited in one of the two, and the vibration component appearing in the other of the first vibration system and the second vibration system is detected among the detected vibrations excited by the vibrator in response to the driving vibration. Features.
[0009]
The inventor has conducted basic research on the vibration principle of a vibrator that can be used in a vibratory gyroscope. In this process, the inventors have succeeded in developing a vibrator and a vibratory gyroscope based on the new principle. This point will be described with reference to one embodiment of FIGS.
[0010]
FIG. 1 is a perspective view schematically showing a vibrating gyroscope including a piezoelectric single crystal vibrator 1A according to an embodiment of the present invention. 2A is a circuit diagram showing the form of the detection electrode, FIG. 2B is a circuit diagram showing the form of the drive electrode, and FIG. 3 shows the form of detection vibration of the vibrator 1A. It is a perspective view.
[0011]
Here, O is the intersection of the Z axis and the predetermined plane of the vibrator, GO is the center of gravity of the whole vibrator (when not vibrating), and GD is the whole center of gravity of the vibration of the drive vibration system.
[0012]
The base 2A of the vibrator 1A has, for example, a two-fold symmetric rectangle around the center of gravity GO of the vibrator. Two first vibration systems 3A and 3B (drive vibration system in this example) protrude from the peripheral edge of the base 2A. Four second vibration systems 6A, 6B, 6C, and 6D (in this example, detection vibration systems) project in a direction perpendicular to the vibration systems 3A and 3B. The vibration systems are separated from each other and are connected via the base 2A.
[0013]
The drive vibration systems 3A and 3B have a base2AThe support part 5 which protrudes from the peripheral part of this and the bending vibration piece 4A, 4B, 4C, 4D extended in the direction orthogonal to the support part 5 from the front end side of the support part 5 are provided. Each of the detection vibration systems 6A-6D includes a bending vibration piece.
[0014]
The bending vibration pieces 6A-6D are provided with detection electrodes 8a, 8b, 8c, 8d as shown in FIG. 2A, and each detection electrode is connected to a detection terminal. The bending vibration pieces 4A, 4B, 4C, and 4D are provided with drive electrodes 7A and 7B as shown in FIG. 2B, respectively, and these are connected to an AC power source.
[0015]
An AC voltage is applied to each of the drive electrodes 7A and 7B, and vibration AX in the X-axis direction is excited on each bending vibration piece of the vibrator 1A. Here, the vibration in the drive vibration system 3A and the vibration in the drive vibration system 3B are set in opposite phases. In this state, when the vibrator 1A is rotated around the Y axis as indicated by ΩY, the vibration BZ in the Z-axis direction is excited in each bending vibration piece as shown in FIG. Correspondingly, the detected vibration CZ in the Z-axis direction is excited in each bending vibration piece 6A-6D. The vibration in the bending vibration pieces 6A and 6B and the vibration in the bending vibration pieces 6C and 6D are in opposite phases. The distortion by each bending vibration piece is detected by the detection electrodes 6A-6D.
[0016]
In all of the conventional vibration type gyroscopes, the drive vibration of the drive vibration arm has some sort of influence on the detection arm as distortion, and noise is generated in the detection signal. According to the present invention, such noise inevitably generated in the detection signal can be suppressed or prevented. In this respect, the present invention solves the fundamental problem inherent in the vibration type gyroscope.
[0017]
In the present invention, the vibrator extends in the predetermined plane. However, this does not mean that the vibrator extends in the predetermined plane in a strict geometric sense. This means that the vibrator is formed within a thickness of 1 mm or less.
[0018]
The first vibration system preferably includes a support portion protruding from the base portion and a flexural vibration piece extending in a direction intersecting the support portion. In this case, the crossing angle is preferably 45 ° to 135 °, particularly preferably 70-100 °, and more preferably vertical. When this angle changes, the natural resonance frequency of the vibration mode of each bending vibration piece 4A-4D changes slightly.
[0019]
The vibrator of the present invention can be used to rotate around a rotation axis extending at least along a predetermined plane, that is, the X axis or the Y axis.
[0020]
Particularly preferably, a plurality of first vibration systems 3A and 3B are provided, and each X-axis vibration system is provided at a rotationally symmetric position around the center of gravity GO of the vibrator. For example, in FIG. 1, the first vibration systems 3A and 3B are two-fold symmetric about the center of gravity GO of the vibrator.
[0021]
Here, each vibration system being in a rotationally symmetric position with the center of gravity GO as the center means a state where a plurality of vibration systems in question are separated from each other by the same predetermined angle within a predetermined plane with the center of gravity GO as the center. . Therefore, when an operation is performed to rotate one vibration system by a predetermined angle within a predetermined plane, the vibration system is positioned at another vibration system. In FIG. 1, since the first vibration systems 3A and 3B are separated from each other by 180 °, if an operation for rotating the vibration system 3A by 180 ° is performed, the first vibration systems 3A and 3B come to the position of the vibration system 3B.
[0022]
Specifically, the rotational symmetry is preferably a 2-fold symmetry, 3-fold symmetry, or 4-fold symmetry. In addition, by providing a plurality of drive vibration systems at rotationally symmetric positions with the center of gravity GO as the center, the influence on relatively small detection vibrations can be particularly suppressed.
[0023]
It is preferable that a plurality of second vibration systems are provided, and each second vibration system is provided at a rotationally symmetric position with respect to the center of gravity GO. For example, in FIG. 1, the detection vibration systems 6A and 6D and 6B and 6C are provided at positions that are two-fold symmetrical about the center of gravity GO.
[0024]
In particular, it is preferable that the entire center of gravity GD of the drive vibration system (preferably the first vibration system 3A, 3B) is located in the vicinity of the center of gravity GO, thereby detecting the vibration system (preferably the second vibration system 3A). The influence on the vibration system 6A-6D) can be suppressed. This means that the vibration components of the drive vibration systems 3A and 3B cancel each other.
[0025]
Specifically, the fact that the center of gravity GD of the driving vibration is located in the vicinity of the center of gravity GO of the vibrator may be substantially located on the center of gravity GO, but a circle having a diameter of 1 mm from the center of gravity GO. Means that it exists within.
[0026]
The present inventor conducted eigenmode analysis by the finite element method in order to investigate the influence of the drive vibration and the detected vibration mode on the whole vibrator of the vibrator of FIGS. The vibrator 1A was made of quartz, and the vibration amplitude at each point of the vibrator was obtained as a ratio distribution with respect to the maximum vibration amplitude point.
[0027]
FIG. 4 shows the relative ratio of the amplitude at the maximum vibration in the driving vibration mode of each point of the vibrator, and FIG. 5 shows the relative ratio of the amplitude at the maximum vibration in the detection vibration mode of each point of the vibrator. Show. In FIGS. 4 and 5, regions having different colors indicate regions having ratios with different maximum vibration amplitude points. The orange part is the area with the smallest amplitude.
[0028]
According to FIG. 4, in the vicinity of the connection portion of each support portion 5 to the base portion 2A, a tensile stress is applied with the vibration of each drive vibration system, and deformation is observed. However, the influence of this deformation cancels out each other in the base portion because the respective drive vibration systems 3A and 3B are arranged at a two-fold symmetrical position around the center of gravity GO. For this reason, in the vicinity of the center O of the base and in the detection vibration systems 6A-6D sandwiched between the drive vibration systems, the influence of the drive vibration is not observed.
[0029]
According to FIG. 5, the influences applied to the base 2A from the drive vibration systems 3A and 3B cancel each other. Moreover, the influence exerted on the base portion 2A from each detection vibration system 6A-6D also cancels each other in the base portion 2A because each detection vibration system is arranged at a two-fold symmetrical position around the center of gravity GO. .
[0030]
As a result, in FIG. 1, the influence of the drive vibration and the detection vibration is not observed in the wide area 9A including the center of the base 2A.
[0031]
In a preferred embodiment of the present invention, the vibrator is supported and fixed in a region where the width of the detected vibration is minimum (more preferably in a region where the width of the drive vibration is minimum). Thereby, the detection vibration generated by the Coriolis force can be effectively generated without being attenuated, the Q value of the detection vibration is increased, and the sensitivity can be increased. Since the detected vibration generated by the Coriolis force is small, it is particularly effective to support the vibrator within a region where the amplitude of the detected vibration is minimum in order to increase sensitivity.
[0032]
In this example, from FIG. 3 and FIG. 4, the region where the amplitude of the drive vibration is minimum and the region where the amplitude of the detected vibration is minimum exist in the wide area 9A in the base 2A as shown in FIG. Therefore, the inside of the region 9A is supported and fixed. In general, the inside of the vicinity region 9B of the center of gravity GO of the vibrator is supported.
[0033]
At this time, a specific method for supporting the vibrator is not particularly limited, and any support method and fixing method can be adopted. For example, any known bonding method can be used as a bonding method of the piezoelectric material. As an example, a predetermined support hole is provided in the regions 9A and 9B, and a certain support tool can be inserted into the support hole to fix the vibrator. For example, the support tool can be protruded from a jig for supporting the vibrator, and the support tool can be inserted into the support hole and fixed. When inserting and fixing the support tool into the support hole, a metallized layer is provided on the surface of the support tool and / or a metallized layer is provided on the inner peripheral surface of the support hole, and then the inner periphery of the support tool and the support hole. Solder or braze the surface. Alternatively, the vibrator can be fixed by arranging a resin between the support and the support hole.
[0034]
The support hole may penetrate the vibrator or may not penetrate the vibrator. When the support hole is a through hole penetrating the vibrator, the support tool can be passed through the support hole, but the support tool need not be passed through.
[0035]
Further, when the support hole is not provided in the vibrator, the support tool can be soldered or bonded to the front surface and / or the back surface of the vibrator regions 9A and 9B by resin.
[0036]
Further, in the vibrator and the vibratory gyroscope of this example, as shown in FIGS. 4 and 5, the center of gravity GO of the vibrator is located in the minute displacement portion of the vibrator during driving vibration. Here, the minute displacement portion of the vibrator at the time of driving vibration means a portion having an amplitude of 1/1000 or less of the maximum amplitude at the time of driving vibration.
[0037]
In the vibration type gyroscope of the present invention, one of the first vibration system and the second vibration system is vibrated. Here, when the vibrator is not rotating, the first vibration system and the second vibration system are vibrated. It is preferred that the other of the system does not vibrate substantially. The fact that the vibration system does not substantially vibrate includes, for example, a case where the vibration amplitude of the detection vibration system when the drive vibration is excited is less than 1/1000 of the maximum amplitude of the drive vibration.
[0038]
The material of the vibrator of the present invention will be described. The entire vibrator of the present invention can be formed of the same piezoelectric single crystal. In this case, first, a piezoelectric single crystal thin plate is prepared, and the thin plate is processed by etching and grinding, whereby a vibrator can be manufactured. Each part of the vibrator can be formed by a separate member, but it is preferable to form the part integrally.
[0039]
When a vibrator is formed from a flat plate material, for example, a piezoelectric single crystal flat plate material such as quartz, by an etching process, a protrusion having a specific shape on each constituent piece such as each bending vibration piece of the vibrator, for example, An elongated protrusion may be generated. Strictly speaking, such protrusions cause a decrease in the symmetry of the vibrator planned at the time of design. However, this protrusion may be present, and it is preferable that the height of the protrusion is small. However, if the height of the protrusion is 1/5 or less of the width of the constituent piece of the vibrator, it can be generally used without any problem. The same applies to the case where an asymmetric part other than the protrusion due to other manufacturing causes exists in the vibrator.
[0040]
In addition, when a projection or the like is present on the vibrator as described above, a part of the projection is deleted by laser processing or the like after etching, or a portion other than the projection of the vibrator is deleted by laser processing or the like. Can be adjusted. As a result, the ring vibration systemoverallCenter of gravity, center of gravity of bending vibration piece, drive vibrationsystemofoverallCenter of gravity, detection vibrationsystemofoverallEach position of the center of gravity can be adjusted so that these are located in a region near the center of gravity GO of the entire vibrator.
[0041]
The material of the vibrator is not particularly limited, but crystal, LiNbO_Three LiTaO_Three Lithium niobate-lithium tantalate solid solution (Li (Nb, Ta) O_Three It is preferable to use a piezoelectric single crystal made of a single crystal, a lithium borate single crystal, a langasite single crystal, or the like.
[0042]
Among the single crystals described above, LiNbO_Three Single crystal, LiTaO_Three The single crystal, lithium niobate-lithium tantalate solid solution single crystal has a particularly large electromechanical coupling coefficient. LiNbO_Three Single crystal and LiTaO_Three Compared with single crystal, LiTaO_Three Single crystal is LiNbO_Three The electromechanical coupling coefficient is larger than that of the single crystal, and the temperature stability is better.
[0043]
When the vibrator of the present invention is formed of a piezoelectric material, the vibrator is provided with a drive electrode and a detection electrode. Examples of the piezoelectric material include piezoelectric ceramics such as PZT in addition to the piezoelectric single crystal.
[0044]
Further, the vibrator of the present invention can be formed of a constant elastic metal such as Elinvar. In this case, it is necessary to attach a piezoelectric body to a predetermined portion of the vibrator.
[0045]
The vibrator of the present invention can be formed by a silicon semiconductor process so as to be used in a silicon micromachine in addition to a piezoelectric material and a constant elastic alloy. In this case, electrostatic force or the like is used when driving the vibrator.
[0046]
Specifically, an electrostatic detection electrode can be used. Further, instead of the electrostatic detection electrode, a semiconductor doping region doped with a specific metal is provided, and the piezoresistive element can be configured by this semiconductor doping region. In this case, when the vibrator rotates, a change in resistance value due to stress applied to each piezoresistive element of each bending vibration piece is measured and detected as an index of the rotational angular velocity.
[0047]
The vibrator of the present invention can be provided with a fixed side portion that is separate from the base portion, the first vibration system, and the second vibration system, and can support the fixed side portion. For example, in the vibrator 1B of FIG. 6, the protruding portions 18 are provided between the bending vibration pieces 6A and 6C of the second vibration system and between the bending vibration pieces 6B and 6D in the base portion 2A. The projecting portions 18 are connected to the fixed side portion 12, respectively. Such protrusions and fixed side portions can also be applied to each vibrator as shown in FIGS.
[0048]
In a preferred embodiment of the present invention, as shown in FIG. 1, the vibrator has a base, the center of gravity of the vibrator is located in the base, and the first vibration system, the second vibration system, One or both of them extend from the peripheral edge of the base. In another preferred embodiment of the present invention, for example, as shown in FIG. 7, the vibrator includes a frame portion, and a hollow portion is formed inside the frame portion. One or both of the first vibration system and the second vibration system extend.
[0049]
In the vibrator 1 </ b> C, a hollow portion 17 is formed inside the frame portion 15, and each vibration system protrudes toward the inside of the frame portion 15. In the hollow portion 17, the center of gravity GO of the vibrator and the drive vibration systemThe entireThere is a center of gravity GD.
[0050]
Two first vibration systems 3E and 3F protrude from the inside of the frame portion 15. The drive vibration systems 3E and 3F include a support portion 5 protruding from the inner peripheral edge of the frame portion, and bending vibration pieces 4I, 4J, 4K, and 4L extending in a direction orthogonal to the support portion 5 from the distal end side of the support portion 5. Yes. Four second vibration systems 6I, 6J, 6K, and 6L protrude in a direction perpendicular to the direction of drive vibration of each bending vibration piece 4I-4L. Each of the second vibration systems includes a bending vibration piece. The vibration systems are separated from each other and are connected via a frame portion 15.
[0051]
A driving vibration AX in the X-axis direction is excited in each bending vibration piece 4I-4L of the driving vibration system. Here, the vibration in the drive vibration system 3E and the vibration in the drive vibration system 3F are set to have opposite phases. In this state, when the vibrator 1C is rotated about the Y axis as indicated by ΩY, the vibration BZ in the Z-axis direction is excited in each bending vibration piece 4I-4L. Correspondingly, the detected vibration CZ in the Z-axis direction is excited in each bending vibration piece 6I-6L.
[0052]
In one embodiment of the vibratory gyroscope of the present invention, the first vibration system includes an X-axis vibration system and a Y-axis vibration system, and the X-axis vibration system extends in the X-axis direction extending in a predetermined plane. The Y-axis vibration system includes a vibration component that extends in a predetermined plane and vibrates in the Y-axis direction orthogonal to the X-axis. In this case, in order to detect the rotational angular velocity about the X axis, the relationship between the vibration of the Y axis vibration system and the plane vertical vibration component of the second vibration system is used to rotate around the Y axis. In order to detect the angular velocity, the relationship between the vibration of the X-axis vibration system and the surface vertical vibration component of the second vibration system can be used. FIG. 8 and FIG. 10 to FIG. 11 realize this embodiment.
[0053]
The base 2B of the vibrator 1D in FIG. 8 has a disk shape. Four first vibration systems 3A to 3D (in this example, drive vibration systems) protrude from the peripheral edge of the base 2B. Four second vibration systems 6E, 6F, 6G, and 6H (in this example, detection vibration systems) protrude between the first vibration systems. The vibration systems are separated from each other and are connected via the base 2B.
[0054]
Each of the drive vibration systems 3A to 3D includes a support portion 5 that protrudes from the peripheral edge of the base portion 2B, and a bending vibration piece 4A to 4H that extends in a direction orthogonal to the support portion 5 from the distal end side of the support portion 5. Each detection vibration system 6E-6H is composed of a bending vibration piece.
[0055]
When detecting the rotational angular velocity of the rotational component around the Y axis, the vibration AX in the X axis direction is excited in each bending vibration piece 4A-4D. That is, the drive vibration systems 3A and 3B are used as an X-axis vibration system. The vibration in the driving vibration system 3A and the vibration in the driving vibration system 3B are in opposite phases, and the driving vibrationWhole systemCenter of gravity GD is the vibratorThe entireIs located within the vicinity region 9B of the center of gravity GO. In this state, when the vibrator 1D is rotated around the Y axis as indicated by ΩY, the vibration BZ in the Z-axis direction is excited in each bending vibration piece 4A-4D. Correspondingly, the detected vibration CZ in the Z-axis direction is excited in each bending vibration piece 6E-6H.
[0056]
When detecting the rotational angular velocity of the rotational component around the X axis, the bending vibration pieces 4E, 4F, 4G, and 4H excite the vibration AY in the Y axis direction. That is, the drive vibration systems 3C and 3D are used as a Y-axis vibration system. The vibration in the drive vibration system 3C and the vibration in the drive vibration system 3D are in opposite phases so that the center of gravity GD of the drive vibration is positioned in the vicinity of the center of gravity GO of the vibrator. In this state, when the vibrator 1D is rotated around the X axis as indicated by ΩX, the vibration BZ in the Z-axis direction is excited in each bending vibration piece 4A-4D. Correspondingly, the detected vibration CZ in the Z-axis direction is excited in each bending vibration piece 6E-6H.
[0057]
In one embodiment of the present invention, the vibrator includes a third vibration system, and the center of gravity of the third vibration systemVibrationBut,When centered on the center of gravity of the entire transducer,Within a given planeIn the circumferential directionVibrateCircumferential directionContains vibration components. When this vibrator is used, the rotational angular velocity about the Z axis can be detected using the relationship between the in-plane vibration component of the first vibration system and the in-plane vibration component of the third vibration system. Here, when the vibrator is not rotating, the third vibration system does not substantially vibrate. The fact that the vibration system does not substantially vibrate includes a case where the amplitude of the third vibration is 1/1000 or less of the maximum amplitude of the drive vibration.
[0058]
A vibrator 1E shown in FIG. 9 relates to this embodiment. However, in the vibrator 1E, the forms and operations of the first vibration systems 3A and 3B and the second vibration systems 6A, 6B, 6C and 6D are the same as those shown in FIG. In the vibrator 1E, the third vibration system 10A protrudes between the vibration systems 6A and 6C, and the third vibration system 10B protrudes between the vibration systems 6B and 6D.
[0059]
The rotational angular velocity of the rotational component ΩY around the Y axis is measured as described above. Further, when the vibrator 1E is rotated around the Z axis as indicated by ΩZ, a Coriolis force in a direction perpendicular to both the X axis and the Z axis acts on each bending vibration piece 4A-4D. As a result, bending vibration as indicated by an arrow DY is excited with respect to the support portion 5. Correspondingly, the detected vibration EX in the X-axis direction is excited in each of the bending vibration pieces 10A and 10B.
[0060]
In the vibrator 1F of FIG. 10, four vibration systems 3G, 3H, 3I, 3J (10C, 10D, 10E, 10F) protrude from the center of each side of the peripheral edge of the base 2A. In parallel with the support portions 5 of the vibration systems 3I and 3J, four bending vibration pieces 6A, 6B, 6C, and 6D protrude from the same side as these to constitute a second vibration system. Four bending vibration pieces 6N, 6P, 6Q, and 6R protrude from the same side in parallel with the support portion 5 of the vibration systems 3G and 3H, and constitute a second vibration system. The vibration systems are separated from each other and are connected via the base 2A.
[0061]
Each of the vibration systems 3G, 3H, 3I, and 3J includes a support portion 5 that protrudes from the peripheral portion of the base portion 1A, and bending vibration pieces 4A, 4B, and 4C that extend in a direction perpendicular to the support portion 5 from the distal end side of the support portion 5. 4D, 4N, 4P, 4Q, 4R are provided.
[0062]
The vibration systems 3G and 3H are used as the drive vibration system (X-axis vibration system), the vibration systems 6A-6D are used as the ΩY detection vibration system (second vibration system), and the vibration systems 10C and 10D are detected as ΩZ. By using it as a vibration system (third detection vibration system), it is possible to measure the rotational angular velocity of the rotational component centered on the Y axis and the rotational angular velocity of the rotational component centered on the Z axis.
[0063]
That is, the drive vibration AX in the X-axis direction is excited in each bending vibration piece 4A-4D of the X-axis vibration systems 3G and 3H. At this time, the third vibration systems 10C and 10D are prevented from substantially vibrating when not rotating. In this state, when the vibrator 1F is rotated about the Y axis, vibration BZ in the Z-axis direction is excited in each bending vibration piece 4A-4D. Correspondingly, the detected vibration CZ in the Z-axis direction is excited in each bending vibration piece 6A-6D.
[0064]
When the vibrator 1F is rotated around the Z axis as indicated by ΩZ, a Coriolis force in a direction perpendicular to both the X axis and the Z axis acts on each bending vibration piece 4A-4D. As a result, bending vibration as indicated by an arrow DY is excited with respect to the support portion 5. Correspondingly, the detection vibration EX in the X-axis direction is excited in each support portion 5 of each of the third vibration systems 10C and 10D.
[0065]
Further, as shown in FIG. 11, the vibration systems 3I and 3J are used as the drive vibration system (Y-axis vibration system), the vibration system 6N-6R is used as the ΩY detection vibration system (second vibration system), By using the vibration systems 10E and 10F as the ΩZ detection vibration system (third detection vibration system), the rotation angular velocity of the rotation component around the X axis and the rotation angular velocity of the rotation component around the Z axis can be obtained. It can be measured.
[0066]
That is, the drive vibration AY in the Y-axis direction is excited in each bending vibration piece 4N-4R of the Y-axis vibration systems 3I and 3J. At this time, the third vibration systems 10E and 10F are prevented from substantially vibrating when not rotating. When the vibrator 1F is rotated about the X axis, the vibration BZ in the Z-axis direction is excited in each bending vibration piece 4N-4R. Correspondingly, the detected vibration CZ in the Z-axis direction is excited in each bending vibration piece 6N-6R.
[0067]
When the vibrator 1F is rotated around the Z-axis as indicated by ΩZ, a Coriolis force in a direction perpendicular to both the Y-axis and the Z-axis acts on each bending vibration piece 4N-4R. As a result, bending vibration as indicated by the arrow DX is excited with respect to the support portion 5. Correspondingly, the detection vibration EY in the Y-axis direction is excited in each support portion 5 of each third vibration system 10E, 10F.
[0068]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a vibrator and a vibratory gyroscope that can be used to detect the rotational angular velocity of a rotating system based on a new principle.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a vibrator 1A according to an embodiment of the present invention.
2A is a circuit diagram schematically showing the configuration of detection electrodes and detection circuits in the vibrator 1A, and FIG. 2B is a circuit diagram schematically showing the configuration of drive electrodes and drive circuits. It is.
FIG. 3 is a perspective view showing a form of detected vibration of a vibrator 1A.
FIG. 4 shows a relative ratio of amplitude at the time of maximum vibration in the drive vibration mode of each point of the vibrator 1A.
FIG. 5 shows a relative ratio of amplitude at the time of maximum vibration in the detection vibration mode of each point of the vibrator 1A.
FIG. 6 is a perspective view showing a vibrator 1B according to another embodiment of the present invention.
7 is a perspective view showing a vibrator 1C according to still another embodiment of the present invention, in which a first vibration system and a second vibration system are provided in a hollow portion inside a frame portion 15. FIG. Yes.
FIG. 8 is a perspective view showing a vibrator 1D according to still another embodiment of the present invention, and includes an X-axis vibration system and a Y-axis vibration system as the first vibration system.
FIG. 9 is a perspective view showing a vibrator 1E according to still another embodiment of the present invention, which includes a first vibration system, a second vibration system, and a third vibration system.
FIG. 10 is a perspective view showing a vibrator 1F according to still another embodiment of the present invention, in which a rotational angular velocity of a rotational component around the Y axis and a rotational angular velocity of a rotational component around the Z axis are measured. To do.
FIG. 11 is a perspective view showing a vibrator 1F according to still another embodiment of the present invention, in which a rotational angular velocity of a rotational component around the X axis and a rotational angular velocity of a rotational component around the Z axis are measured. To do.
[Explanation of symbols]
1A, 1B, 1C, 1D, 1E, 1F Vibrator 2
A Base 3A, 3B, 3E, 3F, 3G, 3H First vibration system (X-axis vibration system)
10 3C, 3D, 3I, 3J First vibration system (Y-axis vibration system)
4A, 4B, 4C, 4D, 4I, 4J, 4K, 4
L Bending vibration piece (vibrates in the X-axis direction)
4E, 4F, 4G, 4H, 4N, 4P, 4Q, 4R Bending vibration piece (vibrates in the Y-axis direction)
5 Supporting part 6A-6R Bending vibration piece (second vibration system)
10A-10F Third vibration system AX (X-axis direction drive vibration) AY (Y-axis direction drive vibration)
Vibration excited in the Z-axis direction in the BZ drive vibration system
Detected vibration excited in the Z-axis direction in the CZ detection vibration system
DX Vibration in the X-axis direction excited by the drive vibration system by the rotation component centered on the DX Z-axis Vibration EX Z-axis in the Y-axis direction excited by the drive vibration system by the rotation component centered on the DY Z-axis Detected vibration in the X-axis direction excited by the detection vibration system by the rotational component centered EY Detected vibration in the Y-axis direction excited by the detection vibration system by the rotational component centered on the Z axis

Claims (6)

A vibrator extending in a predetermined plane,
This vibrator has a frame part, and a hollow part is formed inside the frame part,
Each of the drive vibration systems is a two drive vibration system including a support portion that protrudes from the frame portion to the hollow portion, and two bending vibration pieces that extend in a direction orthogonal to the support portion from the front end side of the support portion. Two drive vibration systems that are provided at positions symmetrical with each other about the center of gravity of the vibrator and bend and vibrate in the predetermined plane;
Each detection vibration system includes four detection vibration pieces projecting from the frame portion to the hollow portion, and each of the two pairs of detection vibration pieces is provided at two-fold symmetrical positions around the center of gravity of the vibrator. Four detection vibration systems,
A vibrator comprising: A vibrator extending in a predetermined plane,
This vibrator has a base,
Each of the drive vibration systems is four drive vibration systems including a support portion protruding from the peripheral edge of the base portion, and two bending vibration pieces extending in a direction orthogonal to the support portion from the distal end side of the support portion, Each of the two pairs of drive vibration systems is provided at a position twice symmetrical with respect to the center of gravity of the vibrator, and four drive vibration systems that flexurally vibrate in the predetermined plane;
Each of the detection vibration systems includes four detection vibration pieces that are provided between the four drive vibration systems and protrude from the peripheral edge of the base, and each of the two pairs of detection vibration pieces is centered on the center of gravity of the vibrator. As four detection vibration systems provided at positions symmetrical with each other twice,
A vibrator comprising: A vibrator extending in a predetermined plane,
This vibrator has a base,
Each of the drive vibration systems is two drive vibration systems including a support part protruding from the peripheral edge of the base part, and two bending vibration pieces extending in a direction orthogonal to the support part from the distal end side of the support part, Two drive vibration systems which are provided at positions symmetrical with each other about the center of gravity of the vibrator, and which flexurally vibrate in the predetermined plane;
Each of the first detection vibration systems includes four detection vibration pieces projecting from the peripheral edge portion of the base portion in a direction perpendicular to the support portion of each drive vibration system, and each of the two pairs of detection vibration pieces. Is provided with four first detection vibration systems provided at positions symmetrical with each other about the center of gravity of the vibrator,
Each of the second detection vibration systems includes two detection vibrations provided between the two detection vibration systems of the four detection vibration systems in a direction perpendicular to the support portion of each drive vibration system. Two detection vibration systems, each of which is provided at a position that is symmetrical twice with respect to the center of gravity of the vibrator;
A vibrator comprising: A vibrator extending in a predetermined plane,
This vibrator has a base,
Each of the drive vibration systems is a four drive vibration system including a support portion protruding from the peripheral edge of the base portion, and a bending vibration piece extending in a direction perpendicular to the support portion from the distal end side of the support portion, of which Each of the two pairs of driving vibration systems is provided at a position twice symmetrical with respect to the center of gravity of the vibrator, and four driving vibration systems that flexibly vibrate in the predetermined plane;
Each of the first detection vibration systems includes four detection vibration pieces projecting from the peripheral edge of the base portion in a direction perpendicular to the support portions of one pair of drive vibration systems, and two pairs of detection vibrations among them. Four detection vibration systems in which each of the pieces is provided at a position twice symmetrical with respect to the center of gravity of the vibrator;
Each of the second detection vibration systems is composed of four detection vibration pieces projecting from the peripheral edge of the base portion in a direction perpendicular to the support portion of the other pair of drive vibration systems, and two pairs of the detection vibrations Four detection vibration systems in which each of the pieces is provided at a position twice symmetrical with respect to the center of gravity of the vibrator;
A vibrator comprising: A vibratory gyroscope for detecting a rotational angular velocity of a rotational component centered on a rotational axis extending in parallel with the predetermined plane, comprising the vibrator according to any one of claims 1 to 4. And a vibration gyroscope comprising: excitation means provided in the drive vibration system; and detection means provided in the detection vibration system . A method for detecting a rotational angular velocity of a rotational component centered on a rotational axis extending in parallel to the predetermined plane, wherein the driving vibration is used using the vibrator according to any one of claims 1 to 4. A method for detecting a rotational angular velocity, comprising: exciting a drive vibration in a system; and detecting a vibration component appearing in the detection vibration system among the detected vibrations excited by the vibrator according to the drive vibration.

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