JPS6361114A - Gyroscopic apparatus - Google Patents

Abstract

PURPOSE:To obtain the title apparatus capable of removing external effect and constituting a plurality of the detection objective axes of angular velocity, by connecting an actuator between the first rigid body fixed to a base and the second rigid body connected to said rigid body by parallel flexible beams extending in a predetermined direction. CONSTITUTION:When an actuator 20 is excited, parallel flexible beams 18a, 18b repeat the bending and return in the main bending directions thereof and the first rigid body 16 is fixed to a base 15 and predetermined vibration is generated in the second rigid body 17. When angular velocity acts around the axes in the directions crossing all of the direction of the beams 18a, 18b and a vibration direction at a right angle, acceleration is generated in the rigid body 17 in the axial direction along the direction of the beams 18a, 18b. Said acceleration is detected by an acceleration detection part 26 to make it possible to detect angular velocity.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a gyro device used in attitude control of aircraft, artificial satellites, etc. and in many other fields, and is particularly suitable for detecting angular velocity with high precision. Regarding a gyro device.

[Conventional technology]

There are many types of gyro devices, such as gas rate sensors that use fluid motion and optical fiber gyroscopes that use the Zernack effect of laser light, but among them, vibration type gyro devices have a simple structure and are the most practical. has been made into Hereinafter, a conventional vibration type gyro device will be explained with reference to the drawings.

FIG. 3(a)=(b)t(c) is a perspective view, a side view, and a plan view of a conventional gyro device. In the diagram,
,Y.

Z indicates the coordinate axis. 1 is an elastic beam extending in the X-axis direction; 2 is a support that is fixed to a certain object (for example, an aircraft) and supports the elastic beam 1; 3 is a piezoelectric element provided on the upper surface of the elastic beam 1;
4 is a piezoelectric element provided on the side surface of the elastic beam 1.

When an AC voltage V is applied to the piezoelectric element 3, the piezoelectric element 3
Repeat expansion and contraction in the m direction. As a result, the elastic beam 1 vibrates at a speed ν in the %X-axis direction, as shown by the broken line in FIG. 3(b). In this state, when an angular velocity Ω is applied around the Z-axis, acceleration in the Y-axis direction acts on the elastic beam IK. This acceleration is called Coriolis acceleration. Coriolis acceleration α is given by the following equation.

α=2xΩXI/ ・−・・・・・・・・・・・・・
・・・・・・・・・・・・(1) That is, when an angular velocity Ω is applied around the Z-axis while the elastic beam l is vibrating in the X-axis direction at a velocity ν, as shown in FIG. As shown by the broken line in c)5
When vibration occurs in the 17m elastic beam 1 due to the Coriolis acceleration α shown in equation (1). Therefore, if the acceleration α is detected, the angular velocity Ω can be obtained from equation (1) since the velocity V is known. The acceleration α is detected by detecting the strain in the elastic beam 1 that is proportional to the acceleration α. The strain of the elastic beam 1 is detected by the piezoelectric element 4 which generates a voltage proportional to the strain and the strain of the elastic beam.

As is clear from the above, the gyro device constitutes an angular velocity meter. However, in the above-mentioned gyro device, when some kind of acceleration is applied from the outside, the elastic beam is deflected in the direction in which the acceleration is applied, so this immediately causes an error, and the accuracy is low, making it difficult to put it into practical use. A gyro device that overcomes this point and has been put into practical use is one example,
It is shown in Publication No. 151015. The outline of this device will be explained with reference to FIG.

FIG. 4 is a perspective view of another conventional gyro device. In the figure, 5 is the mounting base, 6a and 6b are drive devices each composed of bimorph piezoelectric elements, and 7-97b is the drive device 6.
g, support part 8a supporting 6b;

8b is a vibrating member made of a bimorph type piezoelectric element. Reference numeral 9 denotes a mounting portion attached to the upper ends of the drive devices 6a, 6b, and includes a mounting member 9a to which the vibration member 8a is mounted and a mounting member 9b to which the vibration member 8b is mounted. The driving devices 6a, 6b extend in the Y-axis direction on the Y-2,000 plane, and the vibrating members 8a, 8b are connected to the driving devices 6a, 6b.
It extends in the X-axis direction in the X-Y plane at an intermediate position.

10 is a lead wire that connects the piezoelectric element electrodes on the same side of the vibrating members 8a and 8b, 11 is an amplifier that amplifies the output of the vibrating members 8a and 8b, and 12 is a demosimulator.

Now, when an AC voltage is applied to the drive devices 6a and 6bK, these drive devices 6a and 6b deform to the left and right (in the X-axis direction) as shown in the figure. axial direction) and in opposite directions (rotational vibration around the Z axis in mutually opposite directions). In this state,
When an angular velocity Ω is applied around @, the vibration members 8a, 8
Coriolis FC as shown is generated in the Z-axis direction at point b, and the vibrating members 8a and 8b are deflected and deformed accordingly.

Since this deflection deformation is a deformation of the piezoelectric element itself, a voltage proportional to the deformation is generated and extracted through the amplifier 11 and the demosimulator 12. From this K, we can know the angular velocity Ω. In this gyro device, even if acceleration in the Z-axis direction is applied from the outside, the vibration members 8a, 8
Since the electrodes on the same side of the piezoelectric element b are differentially connected by the lead wires 10, the output due to the acceleration is canceled out. Therefore, angular velocity can be detected with high accuracy.

[Problem that the invention seeks to solve]

In the gyro device shown in FIG. 4, the drive device 6a.

Bimorph type piezoelectric elements are used as the vibration members 6b and the vibrating members 8a and 8b. By the way, the force generated by the piemoful piezoelectric element is generally weak, and therefore the driving device 6a,
6b and the photographing members 8a and 8b must necessarily be formed into thin plate shapes. Therefore, the drive members 6a, 6b
When acceleration in the X-axis direction or rotational angular velocity around Y41 is applied from the outside, a considerable degree of deformation occurs. When such a deformation occurs, the velocity ν at which the vibrating members 8a, 8bK act changes, the Coriolis acceleration also changes, and an error occurs in the detection of the angular velocity Ω. However, it seems that the above-mentioned gyro device uses one of the bimorph piezoelectric elements constituting the drive devices 6a and 6b for displacement detection, and extracts and corrects the displacement (noise component) caused by external acceleration. However, it is difficult to completely remove the noise component by signal processing calculations.

Similarly, the vibrating members 8a and 8b also undergo large deformations when externally applied acceleration in the Z-axis direction and rotational acceleration around the Y-axis. Of these, deformation due to acceleration in the Z-axis direction is canceled out as described above and is not output, but no countermeasures have been taken for deformation due to rotational acceleration around the Y-axis, and this makes it difficult to detect the angular velocity Ω. This will result in an error.

Furthermore, the above-mentioned gyro device can only detect the angular velocity around one of the three coordinate axes, and in order to detect angular velocities around multiple axes, a plurality of the above-mentioned gyro devices must be arranged by some means. However, such an arrangement requires a large area.

If there is a limit to the installation space, installation will not be possible. When attempting to detect the angular velocity of two or three axes around a certain predetermined point, it is impossible to combine two or three of the above-mentioned gyro devices accordingly.

An object of the present invention is to provide a gyro device that can solve the above-mentioned conventional problems, can eliminate the influence of external acceleration and angular acceleration, and can easily configure multiple axes for detecting angular velocity. It is on offer.

[Means for solving problems]

To achieve the above object, the present invention includes a first rigid body fixed to the pace, a second rigid body coupled to the first rigid body by a parallel flexible beam extending in a predetermined direction, and the second rigid body is connected to the first rigid body by a parallel flexible beam extending in a predetermined direction. The present invention is characterized in that an actuator is connected between the rigid body and the second rigid body, the actuator causes the parallel deflection beam to deflect in its main deflection direction, and an acceleration detector is connected to the second rigid body.

[For production]

When the actuator is excited, the parallel flexible beam repeatedly deflects and returns in its main deflection direction, causing a predetermined motion in the second rigid body. In this state, when an angular velocity acts around an axis in a direction perpendicular to both the parallel flexible beam direction and the vibration direction, acceleration is generated in the a5 axis direction in the parallel flexible beam direction on the second rigid body. By detecting this acceleration with an acceleration detector, the angular velocity can be detected.

As mentioned above, a parallel flexible beam is used for the vibration generating part, and this parallel flexible beam exhibits high rigidity against acceleration and angular acceleration other than the acceleration in the main deflection direction, and the actuator is a first rigid body. and the second rigid body, the parallel flexible beam exhibits high stiffness against accelerations in the main deflection direction, except when excited by the actuator.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIGS. 1(a) and 1(b) are a side view and a bottom view of a gyro device according to an embodiment of the present invention. In this embodiment, the X, Y, and Z axes are determined as shown in the figure (the Z axis is perpendicular to the paper surface). In the figure, 15 is a pace fixed to a certain object (for example, an aircraft).

16 is a rigid body portion fixed to the pace 15, and has an extension portion 16a extending in the X-axis direction and a protrusion portion 16b projecting from the extension portion 16a in the X-axis direction. 17 is the rigid body part 1
6, and like the rigid body part 16, an extending part 17a extends in the X-axis direction.

and a protruding portion 17 protruding from the extending portion 17a in the X-axis direction.
It has b. 18a and 18b are the rigid body part 16 and the rigid body part 17
It is a parallel flexible beam that is parallel to each other, and has a flat plate shape as shown in FIG. 1(b). Rigid body part 16.17
．． Parallel flexible beam 18a.

When 18b is actually constructed, a through hole 19 from which protrusions 16b and 17b project is formed in one rigid block. 20 are protrusions 16b, 17b
This is a piezoelectric actuator consisting of a laminated piezoelectric element mounted in contact with the KlillJ. 21 is a strain gauge attached near the joint between the rigid body part 16 and the parallel deflection beam 18a. Rigid body part 16゜17, parallel flexible beams 18a, 18
b, piezoelectric actuator 20. and strain gauge 21
The driving section 22 is configured by the following.

Parallel flexible beams 18a and 18b are rigid parts 17Vc
It has low rigidity and easily bends against forces in the Y-axis direction, but it has high rigidity against forces in the Y-axis and Z-axis directions, and moments around the Y-axis, Y@, and Z-axes. Almost no deflection occurs. In this case, the main deflection direction of the parallel deflection beams 18a and 18b is the Y-axis direction.

23 is a rigid body part 24a facing the rigid body part 17;

Reference numeral 24b denotes a parallel flexible beam having a flat plate shape and parallel to each other, which connects the rigid body part 17 and the rigid body part 23. 25 is the rigid body part 17
This is a strain gauge attached near the joint of the parallel flexible beam 24b. The parallel flexible beams 24a, 24b are also formed by through holes, similar to the parallel flexible beams 18a, 18b.

Rigid body part 17.23, parallel flexible beams 24 a, 24 b
s and the strain gauge 25 constitute an acceleration detection section 26. The parallel flexible beams 24a and 24b have low rigidity against forces in the X-axis direction, but high rigidity against forces in the Y-axis and Z-axis directions and moments about the Y-axis, the Y-axis, and two axes.

27 is a rigid body portion 28a facing the rigid body portion 16;

Reference numeral 28b denotes a flat plate-shaped parallel flexible beam that is parallel to each other and connects the rigid body part 16 and the rigid body part 27, and 29 is a strain gauge affixed near the joint between the rigid body part 16 and the parallel flexible beam 28a. Parallel flexible beam 28a.

28b is similar to the parallel flexible beams 24a and 24b,
It is formed by a through hole. Both body parts 16, 27. The parallel deflection beams 28a, 28b and the strain gauge 29 constitute a correction section. Parallel flexible beam 28a.

Like the parallel flexible beams 24a and 24b, the beam 28b has low rigidity against forces in the X-axis direction, but high rigidity against forces in other axial directions and all moments.

Next, the operation of this embodiment will be explained. When an alternating voltage is applied to the piezoelectric actuator 20, the piezoelectric actuator 20 expands and contracts, causing the parallel deflection beam 18a.

When 18b is deflected, the rigid body portion 17 is moved at a velocity V by K. In this state, Pace 15 has an angular velocity Ω around two axes.
When this occurs, a Coriolis acceleration α in the X-axis direction expressed by equation (1) is generated in the rigid body portion 17, and the same acceleration α is generated in the rigid body portion 23. Here, when the mass of the rigid body part 23 is M and the force acting on the rigid body part 23 is F, the force F is expressed by the following equation.

F=α◆M ・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・(2) That is, due to the generation of acceleration α, a force F in the axial direction acts on the rigid body portion 23K, and the parallel flexible beams 24a and 24b are proportional to the force PK. and transform. This deformation is detected using a strain gauge 25 as an electrical signal proportional to the amount of deformation.

On the other hand, the amount of deformation of the parallel deflection beams 18a, 18b is extracted using a strain gauge 24 as an electrical signal proportional to the amount of deformation. In this case, since the amount of deformation is proportional to the speed ν of the rigid body portion 17, the extracted electric signal is proportional to the speed flK.

From the above, the output signal of the strain gauge 21 is e.
If the output signal of the strain gauge 25 is el, the speed V,
The angular accelerations are each expressed by the following equations.

v = %< , ・dew/dt ・・・・・・
...... Self... (3) α=, ・
, ・・・・・・・・・・・・・・・・・・・・・・・・
(4) However, m kl 9 kl is mainly the parallel deflection beam 18a.

This is a constant determined by the rigidity of 18b, 24a, and 24b. After all, the angular velocity Ω can be determined by simultaneously substituting the values V and α obtained from the output signal of the equation (1) and the output signal of the equation (4).

Next, let us consider the case in which acceleration and angular acceleration are applied to the gyro device from the outside. First, regarding the drive section 22, there is a parallel flexible beam 18a.

18b is acceleration other than the acceleration in the 5KY axis direction as described above;
It is rigid against angular acceleration. And parallel flexible beam 1
The deformation of 8a and 18b in the Y-axis direction is performed by the piezoelectric actuator 2.
0 movement, and is not deformed by external acceleration vrtc acting in the Y-axis direction. Therefore, the drive unit 22 is not affected by external acceleration or angular acceleration.

On the other hand, regarding the acceleration detection section 261C, the parallel flexible beams 24a and 24b are rigid against accelerations other than the acceleration in the X-axis direction and angular acceleration, but deform in response to acceleration in the X-axis direction. This amount of deformation causes an error in the detection of the angular velocity Ω. In this embodiment, a correction section 30 is provided to correct this error. The operation of the correction section 30 will be explained below.

Now, when the acceleration β in the X-axis direction acts in the direction of the arrow from the outside while the angular velocity Ω is being detected, the rigid body part 23 receives an acceleration (α+β
) A force proportional to K is applied, and the rigid body part 27
A force proportional to the acceleration β will act on the . When such a force acts on the rigid body part 27, the parallel flexible beam 28
a and 28b are deformed in proportion to this force. This deformation is detected using a strain gauge 29 as an electrical signal proportional to the amount of deformation. That is, an electrical signal proportional to the external acceleration β can be obtained. Therefore, by subtracting the output signal of the correction section 30 from the output signal of the acceleration detection section 26, the error caused by the external acceleration β can be removed.
Accurate angular velocity Ω can be determined.

As described above, in this embodiment, the driving section is composed of two rigid body parts, a parallel flexible beam connecting these rigid body parts, and a laminated piezoelectric actuator rigidly connected between the two rigid body parts. No matter what kind of acceleration or angular acceleration is applied, the drive section is hardly affected, and accurate vibration can be applied to one of the rigid body sections, which in turn can contribute to accurate detection of angular velocity. In addition, since the acceleration detection section is constructed with a parallel flexible beam, it is hardly affected by all other external accelerations and angular accelerations except for acceleration in one direction, and Since we installed a correction section to remove the influence of the acceleration, the acceleration detection section can perform accurate detection even if external acceleration or angular acceleration acts, and as a result, the acceleration can contribute to accurate detection. And these driving parts,
The acceleration detection section and the correction section can suppress the effects of external acceleration and angular acceleration, and can detect angular velocity with high accuracy.

Next, use the structure of the drive section in the above embodiment.
An embodiment of a gyro device that can detect angular velocities in three axes around a predetermined point will now be described.

FIG. 2 is an exploded perspective view of a gyro device according to another embodiment of the present invention. In the figure, x, y, and z are coordinate axes, 40 is a drive section structure, 50 is an acceleration detection section structure, and 60 is a correction section structure. The drive section structure 40 includes a central rigid body part 41 and an overhanging rigid body part 42 that extends from the central rigid body part 41 in the X-axis direction.
．． 43. An overhanging rigid body portion 44 overhanging in the Y-axis direction. ．． 45
It is equipped with 46X is each overhanging rigid body part 44.45VC
The provided driving parts 46Y and 46Z are connected to each extending rigid body part 4.
This is a drive section installed at 2°43. Each drive section 46X.

46Y and 46Z are constructed equivalently to the drive section 22 in the previous embodiment, and each has a parallel bending beam, a piezoelectric actuator made of a laminated piezoelectric element, and a strain gauge.

And drive parts 46X, 46Y.

The main deflection directions of 46Z are the X-axis direction, the Y-axis direction, and
This is the Z-axis direction. The drive section structure 40 includes an overhanging rigid section 44.
45, it is fixed to the pace 15.

The acceleration detection unit structure 50 includes a central rigid body part 51 and an overhanging rigid body part 5 extending from the central rigid body part 51 in the X-axis direction.
2,53, overhanging rigid body part 54.55 overhanging in the Y-axis direction
It is equipped with Reference numeral 56X indicates an acceleration detecting section provided on each extending rigid body section 54.55, and 56Y and 56Z indicate acceleration detecting sections provided on each extending rigid body section 52.53. Each of the acceleration detection sections 56X, 56Y, and 56Z has an equivalent structure to the acceleration detection section 26 in the previous embodiment, and each has a parallel deflection beam and a strain gauge. The main deflection directions of the acceleration detection sections 56X, 56Y, and 56Z are the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The acceleration detection section structure 50 is supported between the ends of the overhanging rigid body section 42.degree. 430 of the drive section structure 40 by the fixed section 57.degree. 581C.

The correction section structure 60 has almost the same structure as the acceleration detection section structure 50 described above, and has a central rigid body section 61 . Each overhanging rigid body part 62,6
3,64,65. Each correction section 66X.

Equipped with 66Y and 66Z. The corrector structure 60 has fixed parts 67 and 68 that allow the overhanging rigid body part 44 of the drive part structure 40 to be fixed.
．． 45 is supported between the ends.

Next, the operation of this embodiment will be explained. The operation for detecting the angular velocity Ω2 around the Z axis is as follows. First, when an alternating current voltage is applied to the piezoelectric actuator of the drive section 46Y, the ends of the overhanging rigid body sections 42 and 43 vibrate in the X-axis direction at a speed Uy. With respect to this direction, the drive parts 46X, 4
Since 6Z has high rigidity, it does not have any effect on the vibration. Due to this vibration, the acceleration detection unit structure 50 also
The same vibration occurs through 7°58. When the angular velocity Ω2 around the Z-axis acts in this state, Coriolis acceleration acts in the X-axis direction, and a corresponding force is applied to the drive section structure 40 and the acceleration detection section structure 50. With respect to this force, only the acceleration detection section 56X has low rigidity, and the other structural parts have high rigidity, so the acceleration detection section 56X is rounded and a signal proportional to the amount of deformation is output. From this K, the angular velocity Ω2 can be determined.

In the process of detecting the angular velocity Ω2, when acceleration acts from the outside in the X-axis direction, a force corresponding to the acceleration is applied to the correction section structure 60. Due to this force, only the correction section 66X is deformed, and a signal proportional to the amount of deformation is output. By subtracting this signal from the output signal of the acceleration detection section 56X, the acceleration variation from the outside is removed, and it is possible to obtain an accurate angular velocity Ω2 that is not affected by the acceleration.

Since the detection of the angular velocity Ω around the X-axis, the angular velocity t around the γ-axis, and Ωa is also performed by operations similar to those described above, a description of these detection operations will be omitted.

As described above, in this embodiment, a drive section structure in which each drive section is provided on orthogonal overhanging rigid body sections, an acceleration detection section structure in which each acceleration detection section is provided on orthogonal overhanging rigid body sections, and an acceleration detection section structure in which each drive section is provided on orthogonal overhanging rigid body sections. Since the gyro device is constructed by stacking the correction section structures provided with each correction section, it has the same effect as the example of the rabbit, and can detect the angular velocity of three axes around a predetermined point with one gyro device. , its structure can also be made compact.

In addition, in the description of each of the above embodiments, a laminated piezoelectric element was exemplified as an actuator, but the present invention is not limited to this, and other appropriate actuators may be used.

〔Effect of the invention〕

As described above, in the present invention, the driving part of the J4-ro snow equipment is composed of two rigid parts, a parallel flexible beam connecting them, and an actuator connected between each rigid part.
All external acceleration and angular acceleration effects can be removed.

As a result, angular velocity can be detected with high accuracy. Furthermore, it is possible to detect angular velocities around multiple axes with a compact structure.

[Brief explanation of the drawing]

1(a) and 1(b) are a side view and a bottom view of a gyro device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a gyro device according to another embodiment of the present invention, and FIG. (a)
, (b) and (c) are a perspective view, a side view, and a plan view of a conventional gyro device, and FIG. 4 is a perspective view of another conventional gyro device. 16.17... Rigid body part, 18a, 18b...
... Parallel deflection beam, 20 ... Piezoelectric actuator, 22 ... Drive section, 26 ... Acceleration detection section, 4o ... Drive section structure, 50・・・・・・
...Acceleration detection unit structure. Figure 1 (Q) Figure 2 5 Figure 3 (Q) (b) 2 no ) α Figure 4

Claims (4)

[Claims] (1) a pace, a first rigid body fixed to the pace, a second rigid body connected to the first rigid body by a parallel flexible beam extending in a predetermined direction, the first rigid body and the second rigid body; A gyro device comprising: an actuator connected between the second rigid bodies to cause the parallel deflection beam to deflect in its main deflection direction; and an acceleration detector connected to the second rigid body. (2) In claim (1), the gyro device is characterized in that the actuator is a laminated piezoelectric element mounted between the first rigid body and the second rigid body. . (3) In claim (1), the acceleration detector includes a second rigid body connected to the second rigid body by another parallel flexible beam extending in a direction perpendicular to the extending direction of the parallel flexible beam. 3. A gyro device comprising a rigid body of No. 3 and a detection means for detecting the deflection of the other parallel deflection beam in the main deflection direction. (4) In claim (1), a fourth rigid body is coupled to the first rigid body by yet another parallel flexible beam extending in a direction perpendicular to the extending direction of the parallel flexible beam. . A gyro device, wherein the further parallel deflection beam is provided with detection means for detecting deflection in its main deflection direction.