JPH04102013A - Vibrating gyro and driving method thereof - Google Patents

Abstract

PURPOSE:To adjust the direction of driven vibration of a vibrator exactly and easily without adjusting the vibrator itself mechanically, by providing a plurality of piezoelectric elements for driving at positions deviating from the center of the width direction of the same projected plane of the vibrator. CONSTITUTION:Piezoelectric elements 3a and 3b for driving which have the same polarity are stuck in lateral juxtaposition longitudinally on one surface of a tuning fork 1 which intersects the direction of driven vibration (the direction (x)) thereof perpendicularly, and piezoelectric elements 4 for detection are stuck on a surface parallel to the direction (x). The elements 3a and 3b are connected to terminals of a variable resistor 7, while a driving power source 6 of high frequency is connected to a sliding terminal of the variable resistor 7. When a voltage is impressed on the elements 3a and 3b from the power source 6, the tuning fork 1 vibrates in the direction (x). When an angular velocity around the axis in the direction (z) is given thereto, a Coriolis force in the direction (y) is generated and the tuning fork 1 vibrates in the direction (y). This vibration on the detection side is detected by the elements 4 and the angular velocity is detected from the Coriolis force applied. In the case when the direction of driven vibration of the tuning fork 1 by the elements 3a and 3b deviates slightly, adjustment is conducted by changing the balance of the driving voltage to be impressed on the elements 3a and 3b, by adjusting the variable resistor 7.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vibrating gyroscope that detects angular velocity.

[Conventional technology] FIGS. 7 and 8 show conventional vibrating gyroscopes, respectively.

All of these vibrating gyroscopes are tuning fork type vibrating gyroscopes that use a tuning fork 1 having two arms 1a as a vibrator. Reference numeral 2 denotes a support rod that supports the tuning fork 1. One driving piezoelectric element 3 is attached to one surface perpendicular to the driving vibration direction (X direction) of the tuning fork 1, and the driving piezoelectric element 3 is attached to a surface parallel to the driving vibration direction (
A detection piezoelectric element 4 is pasted on the surface perpendicular to the X direction. When a driving voltage is applied to the driving piezoelectric element 3, the tuning fork 1 vibrates in the X direction, and when an angular velocity around the Z axis is applied to the tuning fork 1, a Coriolis force in the X direction is generated, and this Coriolis force causes the tuning fork 1 to vibrate in the X direction. The tuning fork 1 vibrates in the X direction, and the detection piezoelectric element 4 detects this detection-side vibration, detects the applied Coriolis force, and detects the angular velocity.

In order to improve the detection accuracy of the above vibration gyro,
It is necessary that the actual driving vibration direction of the tuning fork 1 is correctly in the X direction. However, due to the processing accuracy of tuning fork 1 and the attachment of the piezoelectric element, the driving vibration direction does not necessarily match the original driving vibration direction, and may vibrate in a direction that is slightly angularly deviated from the X direction. A leakage voltage was generated in the detection piezoelectric element 4 due to the y-direction component of the vibration.

For this reason, conventionally, when a voltage is applied to the driving piezoelectric element 3 to actually vibrate the tuning fork 1, and when the driving vibration direction of the tuning fork 1 deviates from the original X direction, the tuning fork 1 is moved as shown in FIG. The vibration direction of the tuning fork 1 can be adjusted to the correct direction by cutting a part of it (the part indicated by the arrow (A)), or by making a threaded hole as shown in Fig. 8 and shifting the mass of the screw 5 screwed into this threaded hole. It was mechanically adjusted to match the direction.

Problems to be Solved by the Invention] Like the above-mentioned conventional vibrating gyroscope in which the vibrator is driven by a single drive piezoelectric element, a part of the vibrator is shaved off in order to adjust the driving vibration direction of the vibrator. In a structure that requires mechanical adjustment on the vibrator side, such as by moving the mass of a screw, it is not easy to make the adjustment correctly, and it requires a lot of man-hours.

The present invention has been made in view of the above circumstances, and provides a vibrating gyroscope and a vibrating gyroscope that can accurately and easily adjust the driving vibration direction of a vibrator without using a method of mechanically adjusting the vibrator itself. The object of the present invention is to provide a method for driving a vibrating gyroscope.

[Means for Solving the Problems] The invention of claim 1 which solves the above problems is based on a plurality of drive voltages that are individually applied to positions shifted from the center of the same projection plane of the vibrator in the width direction of the projection plane. This is a vibrating gyroscope characterized by being equipped with a piezoelectric element.

The invention according to claim 2 is the vibrating gyroscope according to claim 1, which includes:
The invention according to claim 3 is characterized in that the same projection plane on which the driving piezoelectric element is provided is a plane perpendicular to the driving vibration direction of the vibrator, in the vibrating gyroscope according to claim 1,
The invention according to claim 4 is characterized in that the same projection plane on which the drive piezoelectric element is provided is two opposing planes parallel to the drive vibration direction of the vibrator. A method for driving a vibrating gyroscope, characterized in that a plurality of driving piezoelectric elements are provided at positions offset from the driving piezoelectric elements, and the driving vibration direction of the vibrator is adjusted to 1IT11al by individually adjusting the driving voltage applied to each driving piezoelectric element. It is.

Note that in the above, the same projection plane of the vibrator includes both the front side and the opposite side (back side) when the vibrator is viewed from one direction.

[Function] In the above configuration, by adjusting the balance of drive voltages applied to a plurality of drive piezoelectric elements provided at positions shifted from the center of the projection plane width direction of the same projection plane of the transducer, one side of the transducer is It is possible to adjust the balance between the driving forces on the one side and on the other side, thereby controlling the driving vibration direction of the vibrator.

In the vibrating gyroscope according to the second aspect, the drive vibration direction is adjusted by adjusting the balance of drive voltages applied to the plurality of drive piezoelectric elements provided on a plane orthogonal to the drive vibration direction of the vibrator.

In the vibrating gyroscope according to claim 3, the driving vibration direction is adjusted by adjusting the balance of the driving voltages applied to the driving piezoelectric elements provided on two opposing surfaces parallel to the driving vibration direction of the vibrator. be exposed.

In this case, since the drive piezoelectric element attached to the plane parallel to the driving vibration direction of the vibrator directly acts on the vibration in the direction perpendicular to the driving vibration direction, it is possible to reduce the vibration in the direction perpendicular to the driving vibration direction. is easy.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 6.

FIG. 1 is a partial example of the vibrating gyroscope according to the second aspect of the present invention, and is applied to a tuning fork type vibrating gyroscope using a tuning fork as a vibrator. Reference numeral 1 denotes a tuning fork having two arms 1a, and reference numeral 2 denotes a support rod. Two driving piezoelectric elements 3a having the same polarity are disposed on one plane perpendicular to the drive vibration direction (X direction) of the tuning fork 1.

3b are lined up left and right in the X direction and pasted vertically, and the detection piezoelectric element 4 is pasted on a plane parallel to the X direction (a plane perpendicular to the X direction). The two drive piezoelectric elements 3a and 3b are
It is connected to two terminals of the variable resistor 7, and a high frequency drive power source 6 is connected to the sliding terminal of the variable resistor 7. Note that, as shown in the figure, the tuning fork 1 made of metal is grounded.

In the above-mentioned vibrating gyroscope, two driving piezoelectric elements 3
When a voltage is applied from the drive power supply 6 to a and 3b, the tuning fork 1 vibrates in the X direction, and when an angular velocity around the Z axis is applied to the tuning fork 1, a Coriolis force in the X direction is generated, causing the tuning fork 1 to vibrate in the X direction. The detection piezoelectric element 4 detects this detection-side vibration, detects the applied Coriolis force, and detects the angular velocity.

If the driving vibration direction of the tuning fork 1 by the driving piezoelectric elements 3a and 3b is slightly deviated from the original X direction in the X' force direction as shown in FIG. 2, for example, the vibration has an X direction component. , this X-direction component is detected by the detection piezoelectric element 4 as a leakage voltage, causing an error in Coriolis force detection. Therefore, it is necessary to adjust the driving vibration direction of the tuning fork 1 so that it is in the X direction. To do this, adjust the variable resistor 7 to balance the driving voltage applied to the two driving piezoelectric elements 3a and 3b. As a result, one side of the arm 1a of the tuning fork 1 in the X direction (driving piezoelectric element 3
This can be done by adjusting the balance of the driving force between the part on the side a) and the other part on the side of the driving piezoelectric element 3b). For example, when the force direction is shifted by X° as shown in FIG. approaches the original vibration in the X direction.

FIG. 3 shows an embodiment of the vibrating gyroscope according to claim 2, which is applied to a vibrating gyroscope using a vibrating bar as a vibrator. The vibrating bar 11 has two support rods 12.
13 supports the vibration nodes. Two drive piezoelectric elements 3a and 3b are attached vertically in the same manner as described above on one surface of the sound bar 11 in the drive vibration direction (X direction), and a detection piezoelectric element 4 is attached on a surface perpendicular to this. A high frequency drive power source 6 is connected to the two drive piezoelectric elements 3a and 3b via a variable resistor 7.

In the second sound piece type vibrating gyro, the drive piezoelectric element 3
When a driving voltage is applied to a and 3b, the vibrating bar 11 vibrates in the X direction, and when an angular velocity around the Z axis is applied, a Coriolis force in the X direction is generated, and this Coriolis force is transmitted to the detection piezoelectric element 4.
is detected.

If the driving vibration direction of the vibrating bar 11 by the two driving piezoelectric elements 3a and 3b is deviated from the X direction, adjust the variable resistor 7 in the same way as described above, and adjust the driving piezoelectric elements 3a and 3b. By adjusting the balance of the drive voltage applied to 3b, the drive vibration direction can be corrected to the original X direction.

In each of the embodiments shown in FIGS. 1 and 3 described above, two drive piezoelectric elements are provided on one surface of the same projection surface, but one drive piezoelectric element is provided on one surface of the same projection surface. On one side,
Another driving piezoelectric element can also be provided on the opposite surface. In this case, the drive piezoelectric elements provided on the two opposing surfaces are provided at positions shifted in opposite directions from the center in the width direction of the projection surface.

FIG. 4 shows an embodiment of the vibrating gyroscope according to claim 3. This vibrating gyro has a driving vibration direction (X direction) of the vibrating bar 11.
Two driving piezoelectric elements 3a, 3c are placed on one of two opposing surfaces parallel to
, and two driving piezoelectric elements 3b and 3d and one detection piezoelectric element 4 in the center are similarly pasted on the other side. In this embodiment, two driving piezoelectric elements 3a, 3b (or 3b, 3d) on one surface and one
The three piezoelectric elements including the detection piezoelectric element 4 have a single-piece structure in which the piezoelectric plate part is common and the electrode part is divided into three parts.

And, similarly to the above, each driving piezoelectric element 3a.

3b, 3c, and 3d are connected to a drive power source 6 via a variable resistor 7. In this case, the driving piezoelectric elements 3a and 3c (or 3b and 3d) on the same side are connected to the same terminal of the variable resistor 7 with opposite polarity, and the driving piezoelectric elements 3a and 3b (or 3c) on the opposite side are connected to the same terminal of the variable resistor 7. and 3d) have the same polarity and are connected to different terminals of the variable resistor 7.

In the above-mentioned vibrating gyroscope, each driving piezoelectric element 3a,
When a voltage is applied to 3b, 3c, and 3d from the driving power source 6, one side of the vibrating bar 11 in the X direction closes to the driving piezoelectric element 3a.
, 3b side) and the other side drive piezoelectric element 3.
Since the expansion and contraction of the portion on the C23d side is opposite, the vibrating bar 11 is deflected and deformed in the X direction, thereby vibrating in the X direction. Here, when an angular velocity around the Z-axis is applied to the vibrating bar 11, the vibrating bar 11 vibrates in the X direction, and the detection piezoelectric element 4 detects this to detect Coriolis force.

If the driving vibration direction of the vibrating bar 11 deviates from the original X direction, the variable resistor 7 is adjusted to balance the voltages applied to the driving piezoelectric elements 3a, 3C and 3b3d on the opposing surfaces. By changing it, the balance of the driving force between one side of the vibrating bar 11 in the X direction (the part on the driving piezoelectric elements 3a and 3b side) and the other one side part (the part on the driving piezoelectric element 3c and 3d side) is adjusted. , the driving vibration direction of the sound bar 11 can be corrected to the original driving vibration direction (X direction). In this case, the drive piezoelectric element attached to the plane parallel to the drive vibration direction (X direction) directly acts on the vibration in the direction perpendicular to the drive vibration direction, so vibration can be easily reduced, and leakage voltage to the detection piezoelectric element 4 can be reduced.

FIG. 5 shows another embodiment of the vibrating gyroscope according to claim 3.

This vibrating gyroscope has one driving piezoelectric element 3 on one of two opposing surfaces parallel to the driving vibration direction of the vibrating bar 11.
A and one detection piezoelectric element 4 are attached to the other surface, and one drive piezoelectric element 3b and one detection piezoelectric element 4 are attached to the other surface, respectively, and the drive piezoelectric elements 3a and 3b are connected to each other. The detecting piezoelectric elements 4 are pasted so as to be opposed to each other while being shifted in the same direction from the center in the width direction of the surface. and the two driving piezoelectric elements 3a,
3b have the same polarity and are connected to the drive power source 6 via the variable resistor 7. Note that the drive piezoelectric element and the detection piezoelectric element may be independent or may have a one-piece structure divided into two.

In the above-mentioned vibrating gyroscope, two driving piezoelectric elements 3
When voltage is applied to a and 3b from the drive power source 6, the sound bar 11
An elastic force acts on one side of the vibrating bar 11 in the X direction (the part on the side where the drive piezoelectric elements 3a and 3b are located), causing the vibrating bar 11 to vibrate in the X direction.

If the driving vibration direction of the vibrating bar 11 deviates from the original X direction, adjust the variable resistor 7 in the same way as described above to change the balance of the voltages applied to the two opposing driving piezoelectric elements 3a and 3b. to adjust the driving vibration direction of the vibrating bar 11.

Similar to the one in FIG. 4, the driving piezoelectric elements 3a and 3b attached to the plane parallel to the driving vibration direction (X direction) directly act on the vibration in the direction perpendicular to the driving vibration direction, so that the vibrating bar 1
Vibration in a direction perpendicular to the first drive vibration direction can be easily reduced.

Note that the above two driving piezoelectric elements 3a and 3b may be arranged at positions forming diagonal lines in two planes parallel to the driving vibration direction. In this case, the two driving piezoelectric elements 3a and 3b
, 3b have opposite polarities.

FIG. 6 shows an example applied to a tuning fork-type vibrating gyroscope, in which driving piezoelectric elements 3a are placed on one side from the center of each of two opposing surfaces parallel to the driving vibration direction (X direction) of one arm 1a of the tuning fork 1. , 3b are attached, and a detection piezoelectric element 4 is attached to the opposing surface 2-) of the other arm 1a, which is also parallel to the driving vibration direction. Further, the driving power source 6 is connected to the two driving piezoelectric elements 3a and 3b via the variable resistor 7 in the same manner as described above.

When a driving voltage is applied to the two driving piezoelectric elements 3a and 3b, the arm 1a bends and deforms in the X direction, causing vibration in the . The method of controlling the driving vibration direction in this case is also exactly the same as in the above case. Although it is preferable in terms of balance that the detection piezoelectric element 4 is attached symmetrically to the position of the drive piezoelectric elements 3a and 3b, it may be attached to the center of the surface instead of to one side.

Note that the driving piezoelectric elements attached to a plane parallel to the drive vibration direction of the vibrator must be at least offset from the center of that plane, but it is also possible to attach them as close to the edges as possible. is effective for generating a large drive displacement (that is, a large drive vibration amplitude).

Furthermore, in the embodiments, vibrating gyroscopes of a vibrating piece type and a tuning fork type have been described, but the invention can of course be applied to an H-shaped vibrating gyroscope having an H-shaped vibrator.

Further, in the embodiment, the drive voltages applied to the two drive piezoelectric elements vary in relation to each other during adjustment, but it is also possible to adopt a configuration in which they are adjusted independently of each other.

Furthermore, the method of adjusting the drive voltage applied to the two drive piezoelectric elements is not limited to the variable resistor of the embodiment, but also a method using a drive voltage adjustment circuit using an electronic circuit.

In this case, the deviation in the drive vibration direction of the vibrator is detected and fed back to the drive voltage adjustment circuit, and the drive voltage of the two driving piezoelectric elements l\ is adjusted so that the deviation in the drive vibration direction of the vibrator is corrected. Automatic control is also possible.

Furthermore, in the case of a vibrating bar type vibrating gyroscope, it is also possible to set the driving vibration direction of the vibrating bar in a direction parallel to the support rod (for example, the y direction in FIG. 3).

[Effects of the Invention] Since the present invention is configured as described above, it has the following effects.

Since a plurality of driving piezoelectric elements to which driving voltages are individually applied to the same projection plane of the vibrator are provided, the driving vibration direction of the vibrator can be adjusted by individually adjusting the driving voltage applied to each driving piezoelectric element. It becomes possible to control the voltage leakage voltage from the detection piezoelectric element by accurately performing adjustment, and the adjustment operation becomes easy.

Furthermore, in the case where a plurality of driving piezoelectric elements are provided on two opposing surfaces parallel to the driving vibration direction of the vibrator, vibration in the direction perpendicular to the driving vibration direction of the vibrator can be directly reduced, and leakage The voltage can be further reduced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a vibrating gyroscope showing one embodiment of the present invention, Fig. 2 is an explanatory diagram of the drive vibration direction of the vibrator, and Fig. 3 is a vibrating gyroscope showing another embodiment. FIG. 4 is a perspective view of a vibrating gyroscope showing still another embodiment, No. 5112I is a perspective view of a vibrating gyroscope showing still another embodiment, and FIG. 6 is a perspective view of a vibrating gyroscope showing still another embodiment. 7 is a perspective view of a conventional vibrating gyroscope, and FIG. 8 is a perspective view of another conventional vibrating gyroscope. 1. Tuning fork (vibrator)

Claims (4)

[Claims] (1) A vibrating gyroscope characterized in that a plurality of drive piezoelectric elements to which drive voltages are individually applied are provided at positions offset from the center of the projection plane width direction of the same projection plane of the vibrator. (2) The vibrating gyroscope according to claim 1, wherein the same projection plane is a plane orthogonal to the driving vibration direction of the vibrator. (3) The vibrating gyroscope according to claim 1, wherein the same projection planes are two opposing planes parallel to the driving vibration direction of the vibrator. (4) The vibrator is driven by providing a plurality of drive piezoelectric elements at positions offset from the center of the projection plane width direction of the same projection plane of the vibrator, and adjusting the drive voltage applied to each drive piezoelectric element individually. A method for driving a vibrating gyroscope characterized by controlling the direction of vibration.