JPH11281366A - 2-axis angular velocity sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to detect the input angular velocity without influence of the acceleration by driving a ring-like vibration in the diametral direction of orthogonal two axes to mechanically vibrate and detecting the displacement of the ring-like vibration in the diametral direction of the orthogonal two axes. SOLUTION: A conductor semiconductor ring-like vibration 1 with a tetragonal section is fixed to a sensor frame through two pairs of supports 11 which are opposed in the diametral direction and extend in mutually orthogonal directions and composed of metal conductors having a high mechanical strength. A drive element 2 drives and deforms the ring-like vibrator 1 in the diametral direction of two axes x, y to mechanically vibrate a detector element 3 detects the displacement of the ring-like vibrator 1 due to the Coriolis force in a z-axis direction diametral to the axes x, y, a detector circuit 31 arithmetically processes and outputs the input angular velocity from the detect signal of the detector element 3, thereby obtaining a sensor having an elevated detection accuracy, insensitive the acceleration resulting from disagreement of the gravity center of the ring-like vibration 1 from the supports 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-axis angular velocity sensor, and more particularly, to a two-axis angular velocity sensor for simultaneously detecting angular velocities of two orthogonal axes.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. FIG.
In, the flexible substrate 110 is supported by the sensor housing 140 via the flexible supporting portion 121 formed to be thin. The fixed substrate 120 disposed to face the flexible substrate 110 is also supported by the sensor housing 140 around its periphery. The vibrator 1 is located at the center of the lower surface of the flexible substrate 110.
30 is fixed. Further, five lower electrodes F1 to F5 are formed on the upper surface of the flexible substrate 110. On the lower surface of the fixed substrate 120, five upper electrodes E1 to E5 are formed so as to face the five lower electrodes F1 to F5.

An AC voltage is applied between the upper electrode E5 and the lower electrode F5 to apply a mechanical vibration U to the vibrator 130 in the z-axis direction.
z is given. Here, when an angular velocity of ωx is input around the x-axis, the vibrator 13 is generated by the generated Coriolis force Fy.
0 is displaced in the y-axis direction, the capacitance C3 between the upper electrode E3 and the lower electrode F3 increases, and the upper electrode E4 and the lower electrode F3
4, the capacitance C4 decreases. The angular velocity ωx can be detected based on the change in capacitance. ω around y-axis
Even when the angular velocity of y is input, the angular velocity ωy can be similarly detected.

[0004]

In the conventional example of the two-axis angular velocity sensor shown in FIG. 7, since the center of gravity O of the vibrator 130 and the supporting portion 121 do not coincide with each other in the vertical direction, the vertical When acceleration is input in the direction,
The capacitance between the upper electrode and the lower electrode changes under the influence of the acceleration, which makes it difficult to detect the true input angular velocity eliminating the influence of the acceleration.

The present invention provides a two-axis angular velocity sensor that solves the above-mentioned problem.

[0006]

Means for Solving the Problems Claim 1 is provided with a ring-shaped vibrator 1 and a driving element 2 for mechanically vibrating the ring-shaped vibrator 1 by mechanically vibrating the ring-shaped vibrator 1 in two orthogonal diameter directions. Further, a two-axis angular velocity sensor including a detection element 3 for detecting that the ring-shaped vibrator 1 is displaced in a direction perpendicular to two orthogonal axes is configured.

[0007] Claim 2: Claim 1
In the two-axis angular velocity sensor, the driving element 2 has a ring-shaped vibration
High-frequency current source 21 that allows current to flow through a part of element 1₁,
21 _TwoAnd an external magnetic field 4 in a certain direction formed in the z-axis direction
And the two-axis angular velocity sensor constituted by the above. Ma
Claim 3: The two-axis angular velocity sensor according to claim 1.
, The driving element 2 is formed on the outer surface of the ring-shaped vibrator 1.
The driving electrode region 22 to be formed is opposed to the driving electrode region 22.
Fixed electrode 51, drive electrode region 22 and fixed electrode 51
Axis angle composed of a high-frequency drive power supply connected to
A speed sensor was configured.

[0008] Further, claim 4: Claim 2 according to claim 1
In the axial angular velocity sensor, the drive element 2 constituted a two-axis angular velocity sensor including an electrostrictive vibrator 23 bonded and fixed to the inner surface and / or the outer surface of the ring-shaped vibrator 1. Here, claim 5: In the two-axis angular velocity sensor according to any one of claims 1 to 4, the detection element 3 includes the fixed detection electrode 32 and the upper surface and / or the lower surface of the ring-shaped vibrator 1. A two-axis angular velocity sensor which is a capacitor constituted by

Claim 6: In the two-axis angular velocity sensor according to any one of claims 1 to 4, the detecting element 3 is fixedly joined to the upper surface and / or the lower surface of the ring-shaped vibrator 1. 2 which is a strain electrical conversion element 33
The shaft angular velocity sensor was constructed. Claim 7: Claim 3
In the two-axis angular velocity sensor according to any one of claims 6 to 9, both the drive element 2 and the detection element 3 are formed at positions located in the x-axis direction and the y-axis direction of the ring-shaped vibrator 1. A two-axis angular velocity sensor was constructed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the embodiment shown in FIG. 1 is a ring-shaped vibrator,
It is made of a conductor or semiconductor having a square cross section. The ring-shaped vibrator 1 is fixed to a sensor housing (not shown) via two pairs of support portions 11 diametrically opposed to each other. The extending directions of the two pairs of support portions 11 are orthogonal to each other. The support portion 11 is made of a metal conductor having high mechanical strength. Numeral 2 denotes a driving element, which is an element for mechanically vibrating the ring-shaped vibrator 1 by diametrically deforming the ring-shaped vibrator 1 in x and y axes orthogonal to each other. Reference numeral 3 denotes a detection element which detects a displacement of the ring-shaped vibrator 1 due to Coriolis force in the z-axis direction which is a direction perpendicular to the x and y axes orthogonal to each other. Reference numeral 31 denotes a detection circuit which inputs a detection signal of the detection element 3 to calculate and output an input angular velocity.

Here, the operation of the two-axis angular velocity sensor of the present invention will be described. When the ring-shaped vibrator 1 is deformed and vibrated in the diametrical directions of the x and y2 axes orthogonal to each other by the drive element 2, when an angular velocity is input around the x-axis, the position of the ring-shaped vibrator 1 in the y-axis direction is changed. The displaced portion is displaced by receiving a force in the z-axis direction due to the generated Coriolis force. The input angular velocity can be detected by measuring the amount of displacement by the detection element 3.

Hereinafter, a two-axis angular velocity sensor according to the present invention will be described.
Each element to be described will be specifically described. Referring to FIG.
Vibrating in the diametrical direction with respect to the x and y axes
The driving element 2 will be described. 21₁And 21_TwoIs a ring
The vibrator 1 is supported via a support 11 made of a metal conductor.
To allow current to flow through a part of the ring-shaped vibrator 1
FIG. That is, the high-frequency current source 21₁Is
Support part 11₁And support 11_TwoTo the ring
The current is passed through the right four halves of the rotor 1. High frequency current source
21_TwoIs the support 11_ThreeAnd support 11_FourConnect to
Current is passed through the left four halves of the ring-shaped vibrator 1. High lap
Wave current source 21₁And high frequency current source 21 _TwoIs a ring-shaped vibration
The direction of the magnetic flux generated by passing the current through the
The orientation is the same in the vibrator 1. So
Then, an external magnetic field 4 having a fixed direction in the z-axis direction is formed.
And

[0013] Here, when generating the magnetic flux exciting the ring-shaped vibrator 1 by the high-frequency current source 21 ₁ and the high frequency current source 21 _2, the electromagnetic force acts between the magnetic flux generated and the magnetic flux of the external magnetic field 4 The ring-shaped vibrator 1 is mechanically vibrated by being deformed by driving. Referring to FIG. 3, drive element 2
To describe another embodiment, reference numeral 22 denotes a drive electrode region formed on the outer surface of the ring-shaped vibrator 1. The drive electrode regions 22 are formed on a total of four outer surfaces located in the x-axis direction and the y-axis direction of the ring-shaped vibrator 1. Then, a high-frequency driving power source is connected between the driving electrode region 22 and the fixed electrode 51 formed on the peripheral surface of the casing 5, and a driving voltage is applied to generate an electrostatic force between the two electrodes. The drive electrode region 22 is attracted and repelled toward the fixed electrode 51 by electrostatic force generated between the two electrodes. The ring-shaped vibrator 1 is driven and deformed by the suction repulsion, and mechanically vibrates.

Referring to FIG. 4, another embodiment of the driving element 2 will be described. Reference numeral 23 denotes an electrostrictive vibrator fixedly joined to the inner surface and / or the outer surface of the ring-shaped vibrator 1. The electrostrictive vibrators 23 are formed at a total of four places located in the x-axis direction and the y-axis direction of the ring-shaped vibrator 1. As the electrostrictive vibrator 23, a general electrostrictive vibrator in which electrodes are formed by baking electrodes on both surfaces of a porcelain thin plate having a large electrostrictive effect, such as barium titanate and lead zirconate titanate, can be used. A high DC electric field is applied to the porcelain thin plate between the electrodes of the electrostrictive vibrator 23.
After canceling the application of the DC high electric field, the electrostrictive vibrator 2
When a high-frequency power supply is connected to both electrodes 3 and excited, longitudinal vibration is excited in the electrostrictive vibrator 23. In response to the excitation of the longitudinal vibration, the portion of the ring-shaped vibrator 1 where the electrostrictive vibrator 23 is fixed is driven and deformed, and the entire electrostrictive vibrator 23 is mechanically vibrated.

Next, a description will be given of a detecting element for measuring a displacement amount due to Coriolis force with reference to FIG. In FIG. 5, fixed detection electrodes 32 are formed on the upper and lower surfaces of the casing 5 as the detection element 3, and a capacitor is constituted by this and the upper and lower surfaces of the ring-shaped vibrator 1. The condensers are formed at a total of four places located in the x-axis direction and the y-axis direction of the ring-shaped vibrator 1. As described above, when the ring-shaped vibrator 1 is deformed and vibrated in the diametrical directions of the x and y axes orthogonal to each other by the drive element 2, when an angular velocity is input around the x-axis, y of the ring-shaped vibrator 1 is changed. The portion located in the axial direction receives a force in the z-axis direction due to the generated Coriolis force, and is displaced with the adjacent support portion 11 as a fulcrum. Due to this displacement, assuming that the capacitance of the upper capacitor increases and the capacitance of the lower capacitor decreases in one of the fixed detection electrodes 32 located in the y-axis direction, the other of the detection electrodes 32 The capacity of the upper capacitor decreases and the capacity of the lower capacitor increases. When an angular velocity in the opposite direction is input around the x-axis, the increase / decrease of the capacitance of the capacitor is reversed. The magnitude and direction of the input angular velocity can be recognized by detecting the amount of change in the capacitance of the capacitor and the direction of the change between the capacitors. Similarly, the angular velocity input about the y-axis can be detected at the same time.

Referring to FIG. 6, another embodiment of the detecting element will be described. In FIG. 6, as the detecting element 3, a strain-to-electric transducer 33 having the same configuration as the electrostrictive vibrator 23 is used. The child 1 is fixedly joined to the upper surface and / or lower surface of both the portion located in the x-axis direction and the portion located in the y-axis direction. The portion of the ring-shaped vibrator 1 located in the x-axis direction and the portion located in the y-axis direction receive a force in the z-axis direction due to the generated Coriolis force, and are displaced with the adjacent support portions 11 as fulcrums. A voltage proportional to the displacement is generated between the electrodes of the strain electrical conversion element 33, and the magnitude and direction of the input angular velocity can be recognized based on this voltage.

[0017]

As described above, according to the present invention, it is possible to simultaneously detect the angular velocities of two axes orthogonal to each other by using one vibrator, and to determine the center of gravity of the vibrator and the supporting portion. Can provide a two-axis angular velocity sensor with improved detection accuracy that is less susceptible to the acceleration caused by the mismatch between the two.

[Brief description of the drawings]

FIG. 1 illustrates an embodiment.

FIG. 2 is a diagram illustrating an embodiment of a driving element.

FIG. 3 is a diagram for explaining another embodiment of the driving element.

FIG. 4 is a view for explaining still another embodiment of the driving element.

FIG. 5 is a diagram illustrating an example of a detection element.

FIG. 6 is a diagram illustrating another embodiment of the detection element.

FIG. 7 illustrates a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ring-shaped vibrator 11 Support part 2 Drive element 21 ₁ High frequency current source 21 ₂ High frequency current source 22 Drive electrode area 23 Electrostrictive vibrator 3 Detection element 31 Detection circuit 32 Fixed detection electrode 33 Strain electric conversion element 4 External magnetic field 5 Casing 51 fixed electrode

Claims (7)

[Claims] 1. A driving device comprising: a ring-shaped vibrator; and a drive element for mechanically vibrating the ring-shaped vibrator by mechanically vibrating the ring-shaped vibrator in two orthogonal diametral directions. A two-axis angular velocity sensor, further comprising a detecting element for detecting that the ring-shaped vibrator has been displaced. 2. The two-axis angular velocity sensor according to claim 1, wherein the driving element is a high-frequency current source that causes a current to flow through a part of the ring-shaped vibrator and an external magnetic field that is formed in the z-axis direction and has a fixed direction. And a two-axis angular velocity sensor. 3. The two-axis angular velocity sensor according to claim 1, wherein the driving element includes a driving electrode region formed on an outer surface of the ring-shaped vibrator, a fixed electrode facing the driving electrode region, and a driving electrode region. And a high-frequency driving power supply connected to the fixed electrode. 4. The two-axis angular velocity sensor according to claim 1, wherein the driving element is constituted by an electrostrictive vibrator bonded and fixed to an inner surface and / or an outer surface of the ring-shaped vibrator. 2-axis angular velocity sensor. 5. The two-axis angular velocity sensor according to claim 1, wherein the detecting element includes a fixed detecting electrode and an upper surface and / or a lower surface of the ring-shaped vibrator. A two-axis angular velocity sensor, characterized in that: 6. The two-axis angular velocity sensor according to claim 1, wherein the detecting element is a strained electric transducer that is fixedly attached to an upper surface and / or a lower surface of the ring-shaped vibrator. A two-axis angular velocity sensor. 7. The two-axis angular velocity sensor according to claim 3, wherein both the drive element and the detection element are located in the x-axis direction and the y-axis direction of the ring-shaped vibrator. A two-axis angular velocity sensor characterized by being formed there.