JPH11281363A - Angular velocity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angular velocity sensor of a multi-axial detection type by a vibration gyro system. SOLUTION: The angular velocity sensor 100 has a plate-like fixed base 101, plate-like vibration ring 102 and six plate-like supports 103A-103F extending radially from the fixed base at equal distances for supporting the vibration ring. Threes of the six supports are driven so as to vibrate the vibration ring in the circumferential direction, and the remaining three supports having functions to detect the vibration in a perpendicular direction to the main plane, thereby detecting the rotation angular velocity with centers at two axes in the main plane of the angular velocity sensor 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity sensor and, more particularly, to a multi-axis detection type angular velocity sensor using a vibrating gyro system.

[0002]

2. Description of the Related Art FIG. 9A is a perspective view showing an example of a conventional angular velocity sensor as a background of the present invention, and FIG.
Is a sectional view thereof. The angular velocity sensor 900 is
01. The vibrating body 901 is formed in, for example, a regular square shape using a constant elastic metal material. Piezoelectric elements 902a, 902b, and 902 are provided at the center of each surface of the vibrating body 901 respectively.
c, 902d are formed. Piezo elements 902a to 90
2d is an example in which electrodes are formed on both sides of a piezoelectric ceramic, for example.

In such an angular velocity sensor 900, a drive signal is applied between two opposing piezoelectric elements 902a and 902c. By this drive signal, the vibrating body 901 is
Bending vibration occurs in a direction perpendicular to the surface on which the piezoelectric elements 902a and 902c are formed. In this state, when the vibrating body 901 rotates around the longitudinal axis, the vibrating body 90
The vibration direction of the piezoelectric element 902 changes accordingly.
b and 902d. By measuring these voltages, the rotational angular velocity can be detected.
(For example, JP-A-3-269316)

[0004]

However, such an angular velocity sensor detects the rotational angular velocity about the axis of the vibrating body, and therefore can measure only the rotational angular velocity about one axis. Did not. Therefore, to measure the rotational angular velocity around axes in multiple directions,
Since a plurality of angular velocity sensors must be used, the cost, weight, space for mounting the angular velocity sensors, and the like increase, and this poses a practical problem.

[0005] Therefore, a main object of the present invention is to provide an angular velocity sensor capable of detecting a rotational angular velocity about a plurality of axes.

[0006]

(1) An angular velocity sensor according to the present invention comprises a plate-shaped fixed base portion, a plate-shaped vibration ring portion,
It has six plate-shaped support portions for supporting the vibrating ring portion and extending radially at equal intervals from the fixed base portion.

(2) In (1), three of the six support portions are driven so that the vibration ring portion vibrates in the circumferential direction, and the remaining three are main surfaces of the vibration ring portion. And a function of detecting vibration in a direction perpendicular to the direction.

(3) In (1) or (2), the fixed base portion, the vibrating ring portion, and the support portion are made of a constant elastic metal material, and a piezoelectric element is formed on a surface of the support portion. It is characterized by.

(4) In the constitution (1) or (2), the fixed base portion, the vibrating ring portion and the support portion are made of a piezoelectric material, and an electrode film is formed on a surface of the support portion. And

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the principle of operation of an embodiment described later will be described.

FIG. 1 is a perspective view showing an embodiment of the present invention. 101 is a fixed part, 102 is a vibration ring part, 1
03A, 103B, 103C, 103D, 103E, 1
03F represents a supporting portion. 1 from support 103A
03F is connected to the vibrating ring 102 radially at equal intervals from the fixed portion 101 and extends. In this figure, the thickness direction of the plate is defined as the Z direction.

The fixing portion 101 has one or both main surfaces fixed to a member or the like with an adhesive or the like. Note that members and the like are not shown in the drawings. On the other hand, the vibration ring 102 is simply connected to the fixed portion 101 by the support portions 103A to 103F, and can easily vibrate.

Using a plurality of the supports 103A to 103F, the vibration shown in FIG. 2 is generated. This vibration is a vibration along the circumferential direction of the vibrating ring 102, and generally vibrates around the center of the fixed portion 101.

FIG. 3 shows the Coriolis force generated when a rotational angular velocity about the first axis acts on the vibrating angular velocity sensor 100 of FIG. 2, and the deformation state of the angular velocity sensor 100 due to the Coriolis force. Show. In this figure, the support 10
3A, 103B and 103C are displaced in the Z direction in the same phase, and the supporting portions 103A and 103D, 103B and 103E, 103
C and 103F are displaced in the Z direction in opposite phases.

FIG. 4 shows the Coriolis force generated when a rotational angular velocity about the second axis acts on the vibrating angular velocity sensor 100 of FIG. 2, and the deformation state of the angular velocity sensor 100 due to the Coriolis force. Show. Here, the first axis and the second axis are perpendicular to each other, and the first axis and the second axis are perpendicular to the Z axis. In this figure, the support portions 103A and 103F are displaced in the Z direction in the same phase, and the support portions 103A and 103D,
C and 103F are displaced in the Z direction in opposite phases. Then, the support portions 103B and 103E hardly displace in the Z direction.

For example, the support portions 103A, 103C, 10
Assume that 3E is used to generate the vibration of FIG. Under this assumption, the support portions 103A, 103C, 103
E is driven in phase. 3 and FIG.
03B can detect only the rotational angular velocity about the second axis. On the other hand, the support portions 103D and 103F
When the Coriolis force due to the rotational angular velocity around the second axis acts, the displacement is the same in the Z direction in the same phase, but when the Coriolis force due to the rotational angular velocity around the first axis acts, Displaced in the Z direction in the opposite phase to the same extent. Thus, by using the difference between the amounts detected from the displacements of the support portions 103D and 103F, it is possible to detect only the rotational angular velocity about the first axis.

This makes it possible to detect the rotational angular velocity about the first axis and the second axis.

(Embodiment 1) An embodiment in which the angular velocity sensor 100 is formed of a constant elastic metal material will be described below. Since the operation principle is as described above, only the electrode configuration will be described below.

FIG. 5 is a view for explaining a support electrode when used for driving. Since the configuration of the driving support is the same, only the support 103A is shown here.

Reference numerals 501a to 501d denote piezoelectric elements on a flat plate. Each of the piezoelectric elements 501a to 501d is formed, for example, by forming electrodes on both sides of a piezoelectric ceramic. It is connected to the. When the piezoelectric elements 501a and 501b contract in the radial direction of the vibrating ring portion 102, a periodic electric signal is applied so that the piezoelectric elements 501c and 501d extend in the same direction. Occur.

Next, FIG. 6 is a diagram for explaining a supporting portion when used for detection. Since the structure of the support for detection is the same, only the support 103B is shown here.

Reference numerals 601a to 601d denote piezoelectric elements on a flat plate, and the piezoelectric elements 601a to 601d are connected to the support portion 103B with an adhesive or the like. For example, +
The Coriolis force in the Z direction acts, and the vibration ring 102
When displaced in the Z direction, the piezoelectric elements 601a and 6
01b extends in the radial direction of the vibration ring portion 102, and the piezoelectric elements 601c and 601d contract in the same direction. When the Coriolis force in the −Z direction acts, the expansion and contraction of the piezoelectric elements 601a to 601d are reversed. The Coriolis force is detected by detecting a periodic voltage generated by the expansion and contraction.

This embodiment is effective for cost reduction by machining.

(Embodiment 2) An embodiment in which the angular velocity sensor 100 is formed of a piezoelectric material will be described below. Since the principle of operation is as described above, only the electrode configuration when quartz is used as the piezoelectric material and the crystal axis of the quartz coincides with the coordinate axis shown in FIG. 1 will be described below.

FIG. 7 is a view for explaining a supporting portion when used for driving. Since the configuration of the driving support is the same, only the support 103A is shown here.

Reference numerals 701a to 701d denote electrode films, made of gold, silver, or the like, and formed on the support 103A by, for example, vapor deposition. Although not shown in FIG. 7, an electrode film having the same configuration also exists on a surface facing the electrode films 701a to 701d, and an in-phase electric signal is applied to the electrodes facing the electrode films.

The electrode films 701a and 701b have the same phase as the electrode films 701a and 701b, and the electrode films 701b and 701d have the same phase.
The vibration shown in FIG. 2 is generated by applying an electric signal having a reverse phase to the signal.

Next, FIG. 8 is a diagram for explaining a supporting portion when used for detection. Since the structure of the support for detection is the same, only the support 103B is shown here.

Reference numerals 801a to 801d denote electrode films, which are made of gold, silver, or the like, and are formed on the support portion 103B by vapor deposition or the like. Although not shown in FIG. 8, an electrode film having the same configuration also exists on a surface facing the electrode films 801a to 801d.

When a Coriolis force acts in the Z direction and the vibrating ring 102 is displaced in the Z direction, the electrode film 801a
Between electrode films 801b and 801c and between electrode films 801b and 801d
And voltages are generated in opposite phases.
By detecting the periodic voltage generated between the electrode films,
Detect Coriolis force.

In this embodiment, the angular velocity sensor 100 can be miniaturized by, for example, photolithography technology, and the electrode film can be formed with high accuracy by vapor deposition technology, which is effective for miniaturization of the angular velocity sensor.

[0032]

As described above, by using the angular velocity sensor 100, it is possible to detect a rotational angular velocity about a plurality of axes. Therefore, there is no need to use multiple angular velocity sensors to measure rotational angular velocities around axes in multiple directions, and the cost, weight, and angular velocity sensors are implemented compared to using conventional angular velocity sensors. Space for performing the operation can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an angular velocity sensor according to the present invention.

FIG. 2 is a diagram illustrating driving vibration of the present invention.

FIG. 3 is a view for explaining detected vibration (around a first axis) of the present invention.

FIG. 4 is a view for explaining detected vibration (around a second axis) of the present invention.

FIG. 5 is an explanatory diagram of an electrode configuration of a driving support portion according to the first embodiment of the present invention.

FIG. 6 is an explanatory diagram of an electrode configuration of a detection support according to the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of an electrode configuration of a driving support portion according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram of an electrode configuration of a detection support portion according to a second embodiment of the present invention.

FIG. 9A is a perspective view showing an example of a conventional angular velocity sensor, and FIG. 9B is a sectional view thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 100 Angular velocity sensor 101 Fixed base part 102 Vibration ring part 103A-103F Support part 501a-501d Piezoelectric element 601a-601d Piezoelectric element 701a-701d Electrode film 801a-801d Electrode film 900 Angular velocity sensor 901 Vibrating body 902a-902d Piezoelectric element

Claims (4)

[Claims] 1. A plate-shaped fixed base portion, a plate-shaped vibration ring portion, and six plate-shaped support portions for supporting the vibration ring portion and extending radially at equal intervals from the fixed base portion. An angular velocity sensor comprising: 2. Three of the six support portions are driven so that the vibrating ring portion vibrates in the circumferential direction, and the remaining three vibrating ring portions vibrate in a direction perpendicular to the main surface. 2. The angular velocity sensor according to claim 1, wherein the angular velocity sensor has a function of detecting the angular velocity. 3. The fixed base portion, the vibrating ring portion, and the support portion are made of a constant elastic metal material, and a piezoelectric element is formed on a surface of the support portion.
Or the angular velocity sensor according to 2. 4. The apparatus according to claim 1, wherein the fixed base, the vibrating ring, and the support are made of a piezoelectric material, and an electrode film is formed on a surface of the support.
An angular velocity sensor as described.