JPH0455714A - Vibration gyroscope - Google Patents

Abstract

PURPOSE:To improve detecting sensitivity by attaching exciting means to a supporting member, and imparting the vibration generated by the exciting means to a vibrating body through a supporting rod. CONSTITUTION:AC voltages are applied from AC power supplies 16a and 16b into exciting piezoelectric elements 15a and 15b. At this time, the power supplies 16a and 16b output the AC voltages whose phase are inverted to each other. Thus, a vibrating body 11 is vibrated in the direction of the axis X through a supporting rod 12 by vibrating a supporting member 11 in the direction of the axis X. Under this state, the vibrating body 11 is excited only in the direction of axis X. When a rotary angular velocity OMEGA is zero, the vibration component does not appear in the direction of axis Y. When the angular velocity OMEGAaround the axis Z is not zero, Coriolis force acts. Therefore, the vibration having the amplitude in proportion to the angular velocity OMEGA and the same frequency as the direction of the axis X is generated in the direction of the axis Y. The vibration is measures as the voltage with a detecting piezoelectric element 13. Thus the angular velocity OMEGA can be detected. In this way, the detecting sensitivity of the rotary angle speed can be improved.

Description

Detailed Description of the Invention [Purpose of the Invention (Industrial Application Field) The present invention detects the rotational angular velocity of a moving body like a gyroscope, and in particular detects the rotational angular velocity of an elastic body in a vibrating state. This invention relates to a vibrating gyroscope that detects rotational angular velocity by measuring changes in vibration state due to the application of force.

(Conventional technology) A conventional example of this type of vibrating gyroscope is shown in FIG.

A vibrating body 1 having a square column shape is made of an elastic member such as metal, and is fixedly supported at two locations, an upper portion and a lower portion, by support rods 2 and 3, respectively. In this case, the vibrating body 1 is supported by the support rods 2 and 3 at positions that become nodes in an excited vibration state, which will be described later, and vibrations are not transmitted to the support rods 2 and 3. In the vibrating body 1, rectangular piezoelectric elements 4 and 5 are attached to the side surface 1a and the adjacent side surface 1b, and an AC voltage of a predetermined frequency is applied to the piezoelectric element 4 by an AC power source 6. At the same time, the piezoelectric element 5
detects a vibration component in a direction perpendicular to the piezoelectric element 5 of the vibrating body 1 and outputs a voltage signal. Here, in the vibrating body 1, its longitudinal direction is assumed to be two axes, the direction perpendicular to the side surface 1a is the X axis, and the direction perpendicular to the side surface 1b is the Y axis.

In such a configuration, when an AC voltage of a predetermined frequency is applied to the piezoelectric element 4 by the AC power source 6, the vibrating body 1 vibrates at a predetermined frequency in the X-axis direction using the portions supported by the support rods 2 and 3 as nodes. Now, in this excited state, the vibrating body 1 does not have a vibration component in the y-axis direction, so the piezoelectric element 5
No voltage signal is output from. In such an excitation state, when the vibrating body 1 is rotated around the two axes at a rotational angular velocity Ω, as is well known, Coriolis force acts as an apparent force, and the vibration occurs at the same frequency as the excitation frequency. y
Axial vibration occurs. This vibration causes the piezoelectric element 5
A stress is applied to the detection direction, and therefore a voltage signal having an amplitude value proportional to the stress is generated. Since it is known that the amplitude value of such a voltage signal is approximately proportional to the rotational angular velocity Ω, the rotational angular velocity Ω can be measured by detecting this. In other words, it functions as a gyroscope.

(Problem to be Solved by the Invention) However, with the above-described configuration, when actually exciting the piezoelectric element 4, not only vibrations in the X-axis direction but also vibrations in the y-axis direction are generated. In this case, a voltage signal is generated in the piezoelectric element 5 for detection even when the rotational angular velocity Ω is not acting. In other words, the detected voltage is not accurately proportional to the rotational angular velocity Ω, which is a factor that reduces detection accuracy.

In addition, since the vibrating body 1 is supported by the support rods 2 and 3, even if it is formed into a square prism shape, the resonance frequency in the X direction and the X direction will be different values, so the detection sensitivity will be reduced. This will cause a decrease in the amount of water. Furthermore, support rod 2
Even if the support rods 2 and 3 are located at the 10th node of the vibrating body, when vibration in the y-axis direction occurs, the support rods 2 and 3 will undergo bending vibration, which is also a factor in reducing detection sensitivity.

In other words, with the conventional configuration, detection of rotational angular velocity based on the above-mentioned detection principle cannot be faithfully realized.

The present invention has been made in view of the above circumstances, and its purpose is to provide a vibrating gyroscope that can realize rotational angular velocity detection faithfully in principle and that can improve detection accuracy and detection sensitivity. .

[Structure of the Invention] (Means for Solving Problem R) The vibrating gyroscope of the present invention includes a rectangular prism-shaped vibrating body made of an elastic member, and an excitation means for vibrating the vibrating body in a direction perpendicular to its longitudinal direction. , detecting means for detecting vibration in a direction perpendicular to the longitudinal direction of the vibrating body and perpendicular to the vibration direction of the excitation means, and detecting vibration in the longitudinal direction of the vibrating body based on a detection signal of the detecting means. The object is a device that detects a rotational component around a rotation center as a rotational angular velocity, and includes a support member made of an elastic material provided with the excitation means, and a support member for supporting the vibrator between the support member and the vibrator. The vibrator is characterized in that it includes a support rod which is provided in the vibrator and transmits the excitation vibration from the excitation means to the vibrator.

(Function) According to the vibrating gyroscope of the present invention, the vibration caused by the excitation means vibrates the support member, and this vibration is transmitted to the vibrating body via the support rod. In this case, since the support rod supports the vibrating body while facing the excitation direction of the vibrating body, vibrations purely in the excitation direction are transmitted to the vibrating body. In other words,
When no rotational angular velocity is acting, vibration components in the direction perpendicular to the excitation direction no longer appear.

When a rotational angular velocity with the longitudinal direction of the vibrating body as the center of rotation is applied, the vibrating body generates vibration with an amplitude proportional to the rotational angular velocity in the detection direction of the detection means due to the action of Coriolika. Since the detection signal from the detection means is proportional to the amplitude of vibration of the vibrating body in the detection direction, by measuring the voltage, the corresponding rotational angular velocity can be detected with high accuracy. In addition, in this case, the shape of the support member can be formed independently of the shape of the vibrating body, so it can be formed to have the same resonance frequency as that of the vibrating body, thereby improving detection sensitivity. be able to.

(Example) Hereinafter, a first example of the present invention will be described with reference to FIG.

The vibrating body] 1 is made of an elastic member in the shape of a rectangular prism, and a support rod 12 is fixed to a pair of opposing side surfaces 11a and llb in a state that vertically penetrates these, and the other pair of opposing sides 11a and A piezoelectric element 13 serving as a detection means for detecting vibration in a direction perpendicular to the side surface 11c is attached to the side surface 11C of the side surface 11C1lid. This vibrating body 1
The support body 12 fixed to the vibrator 1 is supported by an elastic member type frame 14 which is a support member, and the vibrating body 11 is arranged so that its longitudinal direction is upward. The frame body 14 supports the support rod 1
Piezoelectric elements 15a and 15b, which serve as excitation means, are attached to the outer surfaces 14a and 14b on the side where 2 is fixed. These piezoelectric elements 15a, 1.5b are supplied with alternating current voltages whose phases are reversed from each other by externally provided alternating current power supplies 16a, 16b. That is, the piezoelectric element 15a
, 15b are adapted to excite the frame 14 and the vibrating body 11 via the support rod 12 when an alternating current voltage is applied. The excitation state at this time is the piezoelectric element 15
By applying an alternating current voltage with the phases a and 15b reversed, the entire vibrating body 11 is vibrated left and right (in the X-axis direction).

Next, the operation of this embodiment will be explained. Here, the vibrating body 11 will be explained using the following coordinate axes. That is, as shown in the figure, the longitudinal direction of the vibrating body] 1 is aligned with two axes;
Piezoelectric element 15a for excitation.

1 and 5b is the y-axis, and the detection direction of the piezoelectric element 13 for detection is the y-axis. It is assumed that the rotational angular velocity Ω, which will be described later, acts around the y-axis.

First, AC voltage is applied to the excitation piezoelectric elements 15a and 15b from AC power supplies 16a and 16b, respectively. in this case,
As mentioned above, the AC power source 16a.

Since the voltages 16b are AC voltages whose phases are reversed, the piezoelectric elements 15a and 15b, which are arranged opposite to each other, excite vibration in the same direction in the X-axis direction.

In other words, by vibrating the frame 14 in the X-axis direction,
The entire vibrating body 11 is vibrated in the X-axis direction via the support rod 12. In this state, the vibrating body 11 is excited only in the X direction, and when the rotational angular velocity Ω is zero, no vibration component appears in the y direction.

However, when the rotational angular velocity Ω around the two axes is not zero, as is well known, due to the Coriolis force, y
Vibration is generated in the axial direction with an amplitude proportional to the rotational angular velocity Ω and the same frequency as in the X-axis direction. This vibration is detected as a voltage by the detection piezoelectric element 13. In other words, by measuring this voltage, the rotational angular velocity Ω can be detected. In this case, since the vibrating body 11 is supported at the center position of the whole via the support rod 12, and its cross section is square, the resonance frequency is the same in both the X-axis direction and the y-axis direction. be able to. Therefore, by exciting at the resonant frequency in the X-axis direction, the detection sensitivity of the rotational angular velocity Ω can be increased.

According to this embodiment, the excitation piezoelectric element 1.5a
, 15b are attached to the frame 14, and by vibrating the frame 14, the vibrating body 11 is excited via the support rod 12. Therefore, when the rotational angular velocity Ω is not acting in the excited state, the detection direction is Not only can the vibration be reduced to zero, but the resonant frequency of the vibrating body 11 can also be set geometrically.This allows the detection sensitivity to be improved by vibrating at the resonant frequency when the rotational angular velocity Ω acts in the excitation state. can be made higher.

FIG. 2 shows a second embodiment of the present invention, which differs from the first embodiment in that the direction of the frame 14 is 90 degrees around the X axis.
The arrangement state is such that the vibrating body 11 is rotated by 0". Even in this arrangement, the excitation vibration of the vibrating body 11 can be generated in exactly the same manner as in the first embodiment. The effect can be obtained. Also, in this way, the frame 14
Since the arrangement state of can be detected in exactly the same way no matter what angle it is around the y-axis, it can be set at an appropriate angle depending on the installation environment of the device.

FIG. 3 shows a third embodiment of the present invention, which differs from the second embodiment in that a U-shaped support 17 is used as a support member instead of the frame 14. be. Both ends of the support body 17 are fixed to the vibrating body 11 via the support rods 12, and piezoelectric elements 15a and 15b for excitation are attached to both sides. Exactly the same effect can be obtained.

In each of the above embodiments, the piezoelectric element 15 is used as the detection means, but the detection means is not limited to this, and any other device may be used as long as it can obtain an output proportional to the amplitude of vibration, without departing from the gist of the present invention. Various modifications are possible.

[Effects of the Invention] As explained above, according to the vibrating gyroscope of the present invention,
Since the excitation means is attached to the support member and the vibrations from the excitation means are applied to the vibrating body through the support rod, the resonance frequencies in the excitation direction and the detection direction can be easily matched by the geometric configuration. When the rotational angular velocity is not acting, the vibration in the detection direction can be made zero, which has the excellent effect of improving the detection sensitivity.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the overall configuration showing a first embodiment of the present invention, FIG. 2 is a view corresponding to FIG. 1 showing a second embodiment of the present invention,
3 is a diagram corresponding to FIG. 1 showing a third embodiment of the present invention, and FIG. 4 is a diagram corresponding to FIG. 1 showing a conventional example. In the drawing, 11 is a vibrating body, 12 is a support rod, 13 is a detection piezoelectric element (detection means), 14 is a frame (supporting member), 15a,
15b is an excitation piezoelectric element (excitation means), 1.6a, 1
．． 6b is an AC power supply, and 17 is a support body (support member).

Claims (1)

[Claims] 1. A square column-shaped vibrating body made of an elastic member, and an excitation means for vibrating this vibrating body in a direction perpendicular to its longitudinal direction;
a detecting means for detecting vibration in a direction perpendicular to the longitudinal direction of the vibrating body and perpendicular to the vibration direction of the excitation means, and rotating the vibrating body in the longitudinal direction based on a detection signal of the detecting means. In a vibrating gyroscope that detects a rotational component around a center as a rotational angular velocity, a support member made of an elastic material is provided with the excitation means, and a support member is provided between the support member and the vibrator to support the vibrator. A vibrating gyroscope comprising: a support rod for transmitting excitation vibrations from the excitation means to the vibrating body.