JPH10221086A - Angular-velocity detecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the detecting accuracy of every angular velocity in an angular-velocity detecting apparatus which detects an angular velocity around a rotating axis X-X and an angular velocity around a rotating axis Y-Y and which corresponds to the two axes. SOLUTION: Angular-velocity detecting elements 33, 34, 35, 36 which are constituted respectively of a support 36, of support beams 38 and of vibrators 39 are arranged respectively to be a square shape around the central point Q. The extension direction of the support beams 38 at the angular-velocity detecting elements 33, 35 is arranged in parallel with a rotating axis X-X, and the extension direction of the support beams 38 at the angular-velocity detecting elements 34, 36 is arranged in parallel with a rotating axis Y-Y. Therefore, an angular velocity around the rotating axis X-X is detected by the angular- velocity detecting elements 33, 35, and an angular velocity around the rotating axis Y-Y is detected by the angular-velocity detecting elements 34, 36. In addition, when the angular velocity is detected by the angular-velocity detecting elements 33, 35, the remaining angular velocity detecting elements 34, 36 are used as error detecting elements used to detect an ambient temperature or an axis deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity detecting device suitable for use in a gyro mounted on, for example, an automobile or a camera.

[0002]

2. Description of the Related Art A conventional angular velocity detecting device will be described with reference to FIG.

[0003] Reference numeral 1 denotes an angular velocity detecting device manufactured by a micromachining technique. Reference numeral 2 denotes a substrate made of a high-resistance single crystal silicon material and having an insulating film 2A formed by oxidizing the surface.

[0004] Reference numerals 3 and 3 denote a pair of support portions provided on the substrate 2 via the insulating film 2A. The support portions 3 are located on the substrate 2 and are to be described later in the direction of a rotational axis YY (left-right direction). Are spaced apart from each other.

[0005] Reference numerals 4, 4, ... denote two left and right support beams extending from a pair of support portions 3, 3 located on the left and right. Reference numeral 5 denotes a vibrator provided between the pair of support portions 3 and 3 and separated from the surface of the substrate 2, and two vibrators 5 are provided at left and right positions, respectively. The support beams 4 support the respective support portions 3. The vibrator 5 can be displaced in parallel and orthogonal directions with respect to the substrate 2 via the support beams 4.

Reference numerals 6 and 6 denote electrode supports provided on the substrate 2 with the insulating film 2A interposed therebetween.
Are arranged in a direction perpendicular to the rotation axis Y-Y (vertical direction).

[0007] Reference numerals 7 and 7 denote vibration generating electrodes as vibration generating means for vibrating the vibrator 5 in the direction of arrow A1. It is located between and above and below. Here, each of the vibration generating electrodes 7 is provided with a corresponding one of the electrode support portions 7A, 7A,... Provided on the vibrator 5 so as to mesh with the electrode plates 7A while being separated from the respective electrode plates 7A. 6 are provided with electrode plates 7B, 7B,...

On the surface of the substrate 2 located below the vibrator 5, when the vibrator 5 is displaced in the direction of arrow A2 by Coriolis force, detection is performed as displacement detection means for detecting the amount of displacement. Electrodes (not shown) are provided.

Here, the support portions 3, the support beams 4, the vibrator 5, the electrode support portions 6, and the electrode plates 7A and 7B are made of a low resistance doped with impurities such as P, B and Sb. It is formed by etching a simple polysilicon.

The angular velocity detecting device according to the prior art has the above-described configuration, and its operation will be described next.

When vibrator drive signals having phases opposite to each other are applied to the vibration generating electrodes 7, the vibrator 5 vibrates in the direction of arrow A1. When an angular velocity acts on the rotation axis Y-Y in this state, a Coriolis force corresponding to the angular velocity of the rotation is generated, so that the vibrator 5 is displaced (vibrated) in the direction of arrow A2. When the vibrator 5 is displaced in the direction indicated by the arrow A2, the distance between the vibrator 5 and a detection electrode provided below the vibrator 5 changes, and the vibrator 5 and the detection electrode The capacitance between the electrodes changes. By detecting the change in the capacitance, the angular velocity acting on the angular velocity detecting device 1 is calculated.

On the other hand, the above-described conventional angular velocity detecting device 1 detects only the angular velocity around the rotation axis YY.
This is a so-called angular velocity detecting device for one axis. By arranging two sets of supports, vibrators, supporting beams, etc. on the same substrate at 90 degrees from each other, the angular velocity about the rotation axis in the X-axis direction can be improved. For example, Japanese Patent Application Laid-Open No. Hei 5-333038 discloses a so-called two-axis-compatible angular velocity detecting device for detecting an angular velocity around a rotation axis in the Y-axis direction.

Hereinafter, a description will be given of an angular velocity detecting device for two axes as another conventional technique with reference to FIG.

Reference numeral 11 denotes an angular velocity detecting device corresponding to two axes.
Reference numeral 12 denotes a substrate. The substrate 12 is provided with a flat plate portion 13 and a frame portion 14 so as to surround the outer peripheral side of the flat plate portion 13, and a connecting portion between the flat plate portion 13 and the frame portion 14 is provided. Thin part 15
Are formed. Then, by applying a vibration drive signal to the vibration generating piezoelectric element 16 provided on the flat plate portion 13, the flat plate portion 13 vibrates in the direction of arrow B <b> 1 with respect to the frame portion 14.

Reference numeral 17 denotes a first vibrator provided on the flat plate portion 13 via a support beam 18.
In a state where the vibrator 17 is vibrating in the direction of arrow B1 together with 3, when the angular velocity around the rotation axis XX acts, the vibrator 17 is displaced (vibrated) in the direction of arrow B2 by Coriolis force. The displacement of the vibrator 17 is detected by the detecting element 19.

Reference numeral 20 denotes a second vibrator provided on the flat plate portion 13 via a support beam 21.
In the state where the vibrator 20 is vibrating in the direction of arrow B1 together with 3, when the angular velocity about the rotation axis Y-Y acts, the vibrator 20 is displaced (vibrated) in the direction of arrow B3 by Coriolis force. The displacement of the vibrator 20 is detected by the detecting element 22.

The angular velocity detecting device 11 constructed as described above
According to the method, the angular velocity about the rotation axis XX and the angular velocity about the rotation axis YY can be simultaneously detected.

[0018]

In the above-mentioned prior art, the stress generated by the change in the ambient temperature of the angular velocity detector 1 causes the electrode plates 7A and 7B and the support beam 4 to bend or vibrate. The child 5 may be deformed or misaligned. As a result, there is a problem that a detection error occurs due to the influence of the ambient temperature change, and the detection accuracy of the angular velocity decreases.

In order to solve such a problem, means for providing a temperature compensation detecting device separately from the angular velocity detecting device 1,
Means for providing a processing circuit for temperature compensation outside the angular velocity detecting device 1 can be considered, but it is not easy to sufficiently improve the detection accuracy of the angular velocity by adopting any of the means.
Further, there is a new problem that the manufacturing cost increases due to the increase in the number of parts.

In the angular velocity detecting device 1 according to the prior art, as shown in FIG. 6, the rotational axis Y'-Y 'of the angular velocity actually applied to the angular velocity detecting device 1 is determined by the angular velocity detecting device 1.
When the axis is deviated from the normal rotation axis Y-Y set as described above, there is a problem that the angular velocity detection accuracy is reduced. Note that the above-described axis shift may be caused by a position shift or the like when the angular velocity detecting device 1 is installed in, for example, an automobile or a camera.

On the other hand, in another conventional angular velocity detecting device 11 corresponding to two axes, each of the vibrators 17 and 20 is vibrated by vibrating the flat plate portion 13 with the piezoelectric element 16 in the direction of arrow B1.
Are simultaneously vibrated. As described above, since the vibrators 17 and 20 are vibrated at the same resonance frequency and the same phase, when detecting the angular velocity, the vibration of the vibrator 17 and the vibration of the vibrator 20 are mutually different. There is a problem that interference and so-called crosstalk occur.

For example, when an angular velocity about the rotation axis XX acts on the substrate 12, the vibrator 17 vibrates in the direction of arrow B2 due to Coriolis force. Therefore, there is a problem that the detection accuracy of each angular velocity decreases.

The present invention has been made in view of the above-described problems of the prior art, and it is possible to effectively prevent a decrease in the angular velocity detection accuracy due to a temperature change, and to prevent a decrease in the angular velocity detection accuracy due to an axial deviation. It is an object of the present invention to provide an angular velocity detecting device capable of preventing the angular velocity.

It is another object of the present invention to provide an angular velocity detecting device capable of preventing occurrence of crosstalk between the vibrators and improving the angular velocity detecting accuracy.

[0025]

In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a four-element angular velocity detecting element on a single substrate so as to be symmetrical about one point. And an angular velocity detecting device for detecting angular velocities acting around two rotation axes orthogonal to each other in a direction parallel to the substrate, wherein each of the angular velocity detecting elements is fixed to the substrate. A support beam, a support beam having a base end side provided on the support portion and a distal end extending in a direction parallel to the substrate, and a support beam spaced apart from the substrate and supported by a distal end side of the support beam. A vibrator capable of being displaced in a parallel direction and a perpendicular direction with respect to the vibrator, vibration generating means for vibrating the vibrator in a constant vibration direction, and Around the axis of rotation When the speed is applied, it consists of a displacement detector for the oscillator in response to the angular velocity is detected from being moved in a certain displacement direction different from the vibration direction,
Two of the four angular velocity detecting elements are arranged so that their support beams are orthogonal to the one rotational axis to detect the angular velocity acting around the other rotational axis, and the remaining The two angular velocity detecting elements are arranged so that their support beams are orthogonal to the other rotational axis to detect angular velocity acting around one rotational axis.

According to the above configuration, when an angular velocity acts on one of the rotation axes, the vibrators of the two angular velocity detection elements having the support beams arranged in parallel with this rotation axis are displaced by Coriolis force. However, the vibrators of the two angular velocity detecting elements having the support beams arranged in parallel with the other rotation axis are not displaced by Coriolis force. Further, when the angular velocity acts on the other rotation axis, each vibrator of the two angular velocity detection elements having the support beams arranged in parallel to this rotation axis is displaced by Coriolis force, and Each vibrator of the two angular velocity detecting elements having the support beam arranged parallel to the axis is not displaced by Coriolis force.

Thus, when the angular velocity acts on one of the rotation axes, or when the angular velocity acts on the other rotation axis, the angular velocity detection having the support beams arranged in parallel with the respective rotation axes is performed. The transducers of the elements are less likely to buffer each other, and crosstalk can be reduced.

According to a second aspect of the present invention, the vibration generating means of each angular velocity detecting element is configured to vibrate each vibrator at a different phase.

According to the above configuration, crosstalk is suppressed without the vibrations of the vibrators interfering with each other.

[0030]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 4 show an angular velocity detecting device according to a first embodiment of the present invention.

Reference numeral 31 denotes an angular velocity detecting device according to the present embodiment. Reference numeral 32 denotes a substrate, and the substrate 32 is formed of, for example, a high-resistance single-crystal silicon material in a planar shape. An insulating film 3 made of silicon oxide is formed on the surface of the substrate 32.
2A is formed. Note that the substrate 32 may be formed of a glass material.

Reference numerals 33, 34, 35, and 36 denote four angular velocity detecting elements provided on the substrate 32 according to the present embodiment.
The angular velocity detecting elements 33 to 36 detect the angular velocity around the rotation axis XX and the angular velocity around the rotation axis YY acting on the substrate 32 in a parallel direction. The configurations of the angular velocity detecting elements 33, 34, 35, 36 are all the same in terms of element configuration, material, dimensions, and the like.

Here, among the angular velocity detecting elements 33 to 36, the configuration of the angular velocity detecting element 33 will be described as a representative.

Reference numerals 37, 37 denote substrates 3 via an insulating film 32A.
Each of the support portions 37 is disposed on the substrate 32.

, 38 are a pair of support portions 37, 37.
2 shows two left and right support beams extending from the support beam. 39 is a vibrator provided between the pair of support portions 37 and 37 and separated from the surface of the substrate 32;
The vibrator 39 is supported by each of the support portions 37 by two support beams 38, 38, which are respectively disposed at left and right positions. The vibrator 39 can be displaced in a direction parallel or orthogonal to the substrate 32 via the support beams 38.

Numeral 40 denotes a vibration generating electrode as a vibration generating means for vibrating the vibrator 39 in the direction of arrow E5 in FIG. A thin film is formed by depositing a metal thin film of Au, Cr, or the like on 32.

As shown in FIG. 4, the vibration generating electrode 40 is electrically connected to a phase setting circuit 52 described later provided outside the angular velocity detecting device 31. The vibration drive signal W1 output from the phase setting circuit 52 is applied to the vibration generation electrode 40. Thereby, the vibration generating electrode 40 causes the vibrator 39 to vibrate in the direction of arrow E5 in FIG.

41 is located near the center point Q of the substrate 32,
It is an electrode support provided on the substrate 32. Reference numeral 42 denotes a detection electrode as displacement detection means provided between the vibrator 39 and the electrode support 41, and the detection electrode 42
Comb-shaped electrode plates 42A, 42A,... Provided to protrude from the side surface of the vibrator 39 toward the electrode support portion 41.
And a comb-shaped electrode plate 42 protruding from the electrode support portion 41 so as to mesh with the respective electrode plates 42A in a separated state.
B, 42B,...

The detection electrode 42 detects the displacement of the vibrator 39 by detecting the capacitance between the electrode plates 42A and 42B facing each other. That is, in a state where the vibrator 39 is vibrated by the vibration generating electrode 40 or the like, the rotational speed Y-Y is applied to the angular velocity detecting device 31.
When the peripheral angular velocity acts, the vibrator 39 is displaced in the direction of arrow E2 by Coriolis force. Thereby, each electrode plate 4
The capacitance between 2A and 42B changes, and the displacement of the vibrator 39 is detected by detecting the capacitance at this time.

Each of the support portions 37, the support beams 38,
Oscillator 39, electrode support 41 and electrode plates 42A, 42
B is formed by etching low-resistance polysilicon.

Next, the arrangement of the angular velocity detecting elements 33 to 36 will be described.

The angular velocity detecting elements 33 to 36 are respectively arranged in a square with the center point Q in FIG. That is, each support portion 37 of the angular velocity detecting elements 33 to 36 corresponds to a vertex of the square, and each support beam 38 and each vibrator 39 correspond to each side of the square.

Here, the angular velocity detecting elements 33, 35
Are arranged such that the direction of extension of each support beam 38 is parallel to the rotation axis XX and orthogonal to the rotation axis YY. On the other hand, the angular velocity detecting elements 34 and 36
The extending direction of each support beam 38 is arranged so as to be orthogonal to the rotation axis XX and parallel to the rotation axis YY.

Therefore, the angular velocity detecting device 3 according to the present embodiment
1 indicates that when the angular velocity about the rotation axis XX acts on the angular velocity detecting device 31 in a state where the vibrators 39 of the angular velocity detecting elements 33 to 36 are vibrated by the respective vibration generating electrodes 40, the angular velocity detecting elements 33, The 35 oscillators 39 are indicated by arrows E1, E
Displaced in three directions. At this time, the angular velocity detecting elements 34 and 36
Does not displace.

On the other hand, when the angular velocity about the rotation axis Y-Y acts on the angular velocity detecting device 31 in a state where the vibrators 39 of the angular velocity detecting elements 33 to 36 are vibrated by the respective vibration generating electrodes 40, the angular velocity detecting element 34, 36 oscillators 39
Is displaced in the directions indicated by arrows E2 and E4. At this time, the angular velocity detecting elements 33 and 35 are not displaced.

As described above, the angular velocity detecting device 31 can detect the angular velocity around the rotation axis XX by the angular velocity detection elements 33 and 35, and the rotation axis Y by the angular velocity detection elements 34 and 36.
-Angular velocity around Y can be detected.

On the other hand, when the ambient temperature of the angular velocity detecting device 31 changes, each support beam 38 is bent, and each vibrator 39 is deformed or displaced. 39 is displaced independently of the action of the angular velocity. If the change in the ambient temperature is large, the amount of deflection of each support beam 38, the degree of deformation of each vibrator 39, and the like increase, and accordingly, the amount of displacement of each vibrator 39 also increases. Therefore, by detecting the displacement of each transducer 39 of the angular velocity detecting elements 33 and 35 by each detecting electrode 42, data (variable) corresponding to a change in the ambient temperature can be obtained.

As shown in FIG. 3, for example, the rotational axis Y'-Y 'of the angular velocity actually acting on the angular velocity detecting device 31 is shown.
Is shifted from the normal rotation axis Y-Y of the angular velocity detecting device 31, the rotational speed Y'-Y 'of the angular velocity actually acting on the angular velocity detecting device 31 becomes the angular velocity detecting element 3.
The support beams 38 forming the members 3 and 35 are not orthogonal to the extending direction. As a result, when an axis shift occurs,
The vibrators 39 of the angular velocity detecting elements 33 and 35 receive the Coriolis force and are displaced in the directions indicated by arrows E1 and E3. Also, the greater the degree of axis deviation, the greater the displacement of each vibrator 39. Accordingly, the displacement of each oscillator 39 of the angular velocity detecting elements 33 and 35 is determined by each of the detecting electrodes 4.
2, the data (variable) corresponding to the magnitude of the axis deviation can be obtained.

On the other hand, the angular velocity detecting elements 34 and 36 are disposed on the substrate 32 so as to oppose each other in the left-right direction, and the extending directions of the respective support beams 38 and the rotation axis Y-Y are parallel to each other. Are located. Thereby, each vibrator 39 of the angular velocity detecting elements 34 and 36 is connected to the angular velocity detecting device 31.
When an angular velocity about the rotation axis Y-Y acts on, it is displaced in the directions indicated by arrows E2 and E4 in FIG. 1 by Coriolis force.
Therefore, by detecting the displacement of each transducer 39 of the angular velocity detecting elements 34 and 36, data (variable) corresponding to the angular velocity applied to the angular velocity detecting device 31 can be obtained.

Next, an angular velocity detecting circuit provided outside the angular velocity detecting device 31 will be described with reference to FIG.

Reference numeral 51 denotes an oscillation circuit for generating a high-frequency signal;
Reference numeral 2 denotes a phase setting circuit that generates vibration drive signals W1, W2, W3, and W4 based on the high-frequency signal output from the oscillation circuit 51. The phase setting circuit 52 includes a high-frequency signal output from the oscillation circuit 51. Is converted to generate vibration drive signals W1, W2, W3, and W4, which are sine wave signals having the same frequency and shifted in phase by 90 degrees. The vibration drive signals W1, W2, W3, W4 are applied to the vibration generating electrodes 40 of the angular velocity detecting elements 33 to 36, respectively. Thereby, each vibrator 39 vibrates in the direction of arrow E5 in FIG. 2 at the same frequency and in a state where each phase is shifted by 90 degrees.

That is, the vibration of the vibrator 39 of the angular velocity detecting element 33 is 180 degrees out of phase with the vibration of the vibrator 39 of the angular velocity detecting element 35 facing the angular velocity detecting element 33 in the front-rear direction. The vibrators 39 vibrate in opposite phases. The vibration of the vibrator 39 of the angular velocity detecting element 34 is
The phase is shifted by 180 degrees with respect to the vibration of the vibrator 39 of the angular velocity detecting element 36 facing the angular velocity detecting element 34 in the left-right direction, and the vibrators 39 vibrate in opposite phases.

Numerals 53, 53,... Denote amplification circuits composed of differential amplifiers and the like, and a detection signal output from the detection electrode 42 is input to each of the amplification circuits 53. And
Each amplification circuit 53 generates a new detection signal corresponding to the displacement of each oscillator 39 by differentially amplifying each detection signal.

.. Designate a phase detection circuit, and 55 designates an arithmetic processing circuit. Each of the phase detection circuits 54 and 55 includes a detection signal output from each amplifier circuit 53 and each of the phase signals. Based on the vibration driving signals W1, W2, W3, and W4 output from the setting circuit 52, calculations based on the following equations 1 to 4 are performed to correct a detection error due to a temperature change, axis deviation, and the like, and to output an angular velocity. The signal R is output.

Next, a method of calculating the angular velocity detection signal R by the phase detection circuit 54 and the arithmetic processing circuit 55 will be described.

First, the rotational speed Y-Y is applied to the angular velocity detecting device 31.
When the peripheral angular velocity acts, the Coriolis force acting on each vibrator 39 is represented by F1, F2, F3, F4, and the vibration drive signal W
1, the frequency of W2, W3, and W4 (the vibration frequency of each vibrator 39) is ω, the mass of each vibrator 39 is M, the angular velocity applied to the angular velocity detecting device 31 is Ω, and the direction of each vibrator 39 is indicated by arrow E5. Is the amplitude, A is the time, t is the angle of the axis deviation with respect to the rotation axis Y-Y, that is, the rotation axis Y'-Y 'of the angular velocity actually acting on the angular velocity detection apparatus 31 and the angular velocity detection apparatus 31 are set. If the angle between the normal rotation axis YY and θ is θ,
The following equation 1 holds.

[0058]

F1 = 2 · A · M · ω · Ω · cos (90−θ) · co
sωt F2 = −2 · A · M · ω · Ω · cos θ · cos (ωt
−90) F3 = −2 · A · M · ω · Ω · cos (90−θ) · c
os (ωt−180) F4 = 2 · A · M · ω · Ω · cos θ · cos (ωt−
270)

Here, since the axis deviation angle θ is generally small, it can be approximated as sin θ = θ and cos θ = 1. Further, when each of the above equations (1) is DC-converted, the following equation (2) is obtained. Note that 2 · A · M · ω = α.

[0060]

F1 = α · Ω · θ F2 = −α · Ω F3 = −α · Ω · θ F4 = α · Ω

The ambient temperature change components are D1, D2, D
3, D4, and S1, S2, S3, S4 are the numerical values obtained by adding the ambient temperature change component of the angular velocity detecting device 31 to each of the Coriolis forces F1, F2, F3, F4. Here, the numerical values S1, S2, S3, and S4 can be obtained by detecting the displacement of each vibrator 39 of the angular velocity detecting elements 33 to 36 by each detecting electrode 42.

[0062]

## EQU00003 ## S1 = .alpha..OMEGA. + D1 S2 =-. Alpha..OMEGA. + D2 S3 =-. Alpha..OMEGA. + D3 S4 = .alpha..OMEGA. + D4

Here, the angular velocity detecting elements 33 to 36 are arranged in a square shape with the center point Q as the center, and the element configurations, materials, dimensions, etc. of the angular velocity detecting elements 33 to 36 are all the same. It is. For this reason, the bending, deformation, and displacement of each of the support beams 38 and each of the vibrators 39 due to a change in the ambient temperature occur substantially similarly in any of the angular velocity detecting elements 33 to 36. Therefore, the ambient temperature change component D
1, D2, D3 and D4 are D = D1 = D2 = D3 = D4
And the following equation 4 holds.

[0064]

## EQU00004 ## S1 = .alpha..OMEGA..theta. + D S2 =-. Alpha..OMEGA. + DS3 =-. Alpha..OMEGA..theta. + DS4.

The four formulas of the equation (4) represent the angular velocity detecting elements 33 to
36, the displacement of each transducer 39, the angular velocity acting on the angular velocity detecting device 31, the characteristics of the angular velocity detecting elements 33 to 36 with respect to the ambient temperature change, and the characteristics of the angular velocity detecting elements 33 to 36 with respect to the axis deviation. This is a characteristic equation. Then, by solving these four characteristic equations, the angular velocity Ω acting on the angular velocity detecting device 31, the axis deviation angle θ with respect to the rotation axis Y-Y, and the ambient temperature change component D are calculated.

From the above equation (4), the ambient temperature change component D
Can be obtained in two ways. That is, the ambient temperature change component D is the first of the equations (4) relating to S1.
It can be obtained by the expression and the third expression relating to S3, and can also be obtained by the second expression relating to S2 and the fourth expression relating to S4 among the expressions of the above Expression 4. Therefore, each ambient temperature change component D obtained by these two methods in a state where there is no temperature change can be used as a variable for correcting the variation between the vibrators 39. Thereby, the detection accuracy of the angular velocity can be improved.

The angular velocity detecting device 31 according to the present embodiment has the above-described configuration. Next, the overall operation will be described.

First, when the oscillation driving signals W1, W2, W3 and W4 are applied to the respective vibration generating electrodes 40 by the oscillation circuit 51 and the phase setting circuit 52, the respective vibrators 39 are moved in the direction of arrow E5 in FIG. Vibrate. At this time, the vibration drive signal W1,
Since a phase difference of 90 degrees is set for each of W2, W3, and W4, each vibrator 39 vibrates at a different phase by 90 degrees. When an angular velocity around the rotation axis Y-Y acts on the angular velocity detecting device 31 in a state where each of the vibrators 39 vibrates, each of the vibrators 3 of the angular velocity detecting elements 34, 36
9 is displaced (vibrated) in the directions of arrows E2 and E4 in FIG. 1 by Coriolis force.

Further, when the ambient temperature of the angular velocity detecting device 31 changes, or as shown in FIG. 3, the rotational axis Y'-Y 'of the angular velocity actually applied to the angular velocity detecting device 31 is applied to the angular velocity detecting device 31. When the axis is deviated from the set normal rotation axis Y-Y, the vibrators 39 of the angular velocity detecting elements 33 and 35 serving as error detecting elements correspond to the magnitude of the ambient temperature change or the magnitude of the axis deviation. And arrow E in FIG.
It is displaced (vibrated) in the E1 and E3 directions.

The displacement of each transducer 39 of the angular velocity detecting elements 33 to 36 is detected by each detecting electrode 42,
This is output to each amplifier circuit 53 as a detection signal. Further, the detection signal is differentially amplified by each amplifier circuit 53, and the respective phase detection circuits 54 and the arithmetic processing circuit 55 perform calculations based on the above equations (1) to (4). An angular velocity detection error due to the axis deviation is removed, and an angular velocity output signal R corresponding to the true angular velocity is output.

Further, the vibrators 39 of the angular velocity detecting elements 33 and 35 vibrate in opposite phases. Therefore, each vibrator 39 when the angular velocity around the rotation axis XX acts.
If the angular velocity is obtained by adding the displacement amounts of the above, the detection sensitivity of the angular velocity about the rotation axis XX is doubled. Also,
Each vibrator 3 when an angular velocity around the rotation axis Y-Y acts
If the angular velocities are obtained by adding the displacement amounts of 9, the detection sensitivity of the angular velocities around the rotation axis YY doubles.

Thus, according to the present embodiment, the four angular velocity detecting elements 3 having different arrangements on the single substrate 32 respectively.
Since the configuration is provided with 3 to 36, the angular velocity around the rotation axis XX and the angular velocity around the rotation axis YY can be simultaneously detected, and the detection sensitivity of each angular velocity is improved. Accuracy can be improved.

When an angular velocity about the rotation axis XX or an angular velocity about the rotation axis YY acts, the Coriolis force generated by the angular velocity is applied to the angular velocity detecting elements 33 to 36.
Is detected as the displacement of each vibrator 39, and the four characteristic equations shown in the above Expression 4 can be obtained based on the four detection results obtained thereby. By performing calculations based on these four characteristic equations, it is possible to always perform accurate angular velocity detection even if a change in the ambient temperature or an axis shift occurs.

Also, since the vibrators 39 of the angular velocity detecting elements 33 to 36 are configured to vibrate at phases different from each other by 90 degrees, it is possible to prevent the vibrations of the vibrators 39 from interfering with each other. Crosstalk can be prevented from occurring between them. Thereby, noise can be removed from each detection signal output from each detection electrode 42 of the angular velocity detection elements 33 to 36, and the S / N ratio of each detection signal can be improved.

Further, when the angular velocity around the rotation axis XX acts, the detection electrodes 42 of the angular velocity
And the detection signals output from the detection electrodes 42 of the angular velocity detecting elements 34 and 36 when the angular velocity around the rotation axis YY acts on the detection signals can be easily resolved. , The angular velocity around the rotation axis XX and the rotation axis Y−
The angular velocities around Y can be independently taken out. As a result, the performance of the two-axis facing angular velocity detecting device can be greatly improved.

On the other hand, according to the present embodiment, the angular velocity detecting elements 33 and 35 are set so that the extending direction of each support beam 38 is the rotation axis YY.
, The angular velocity detecting elements 33 and 35 can be used as error detecting elements for detecting a change in ambient temperature and an axis deviation.

Further, since the angular velocity detecting elements 34, 36 are arranged so that the extending direction of each support beam 38 is orthogonal to the rotation axis XX, the angular velocity detecting elements 34, 3
6 is used as an error detection element for detecting a change in ambient temperature and an axis shift.

As a result, it is possible to perform temperature compensation and axis deviation correction when detecting angular velocities around the two axes of the rotation axis XX and the rotation axis YY, and to reduce the size of the angular velocity detector 31. it can.

Further, according to the present embodiment, the angular velocity detecting elements 33 to 36 are arranged in a square with the center point Q as the center, so that
Even when the angular velocity detecting device 31 is manufactured by an etching process or the like with a good balance of directions, dimensional variations of the vibrators 39, the support beams 38, and the electrode plates 42A and 42B can be minimized, and each vibration It is not necessary to adjust the resonance frequency of the element 39.

Further, according to the present embodiment, the angular velocity detecting elements 33 and 35 are arranged so that the respective support beams 38 are parallel to each other.
And the rotational axis YY have the same positional relationship. Further, the angular velocity detecting elements 34 and 36 are connected to the respective support beams 38 of both.
Are arranged so as to be parallel to each other, so that the positional relationship between the angular velocity detecting elements 34 and 36 and the rotation axis YY becomes equal.

Thus, for example, the angular velocity detecting device 31
When there is no change in the ambient temperature such as immediately after the power is turned on, the displacement of each of the vibrators 39 constituting the angular velocity detecting elements 33 to 36 is detected, and the respective detection results are compared. It is possible to correct an error in the amount of displacement due to the dimensional variation of 39 and the like.

Next, an angular velocity detecting device according to a second embodiment of the present invention will be described with reference to FIG. 5. The feature of this embodiment is that four angular velocity detecting elements are radially arranged around one point. It is located in.

Reference numeral 61 denotes an angular velocity detecting device according to the present embodiment. Reference numeral 62 denotes a substrate. The substrate 62 is formed of a high-resistance single-crystal silicon material, similarly to the substrate 32 of the first embodiment.

Reference numerals 63, 64, 65 and 66 denote four angular velocity detecting elements provided on the substrate 62. The angular velocity detecting elements 63 to 66 are radially arranged at 90 ° intervals around the center point Q. And an angular velocity about a rotation axis XX acting in a direction parallel to the substrate 62 and a rotation axis YY
This is to detect the angular velocity around.

Here, the configurations of the angular velocity detecting elements 63 to 66 have the same element configuration, material, dimensions, and the like, respectively. The specific configuration will be described using the angular velocity detecting element 63.

The angular velocity detecting element 63 has the same configuration as the angular velocity detecting element 33 described in the first embodiment.
A support portion 67 provided on four sides of the substrate 62 and a support portion 68 provided near the center point Q of the substrate 62
And four support beams 69 provided between the support portions 67 and 68, a vibrator 70 oscillated by the respective support beams 69, and a lower position of the vibrator 70. Electrodes for vibration generation (not shown) as vibration generating means formed on the surface of the substrate 62 and electrode support portions 71, 71 provided on the substrate 62 at both sides of the vibrator 70.
And a detection electrode 72, 72 as a displacement detection means formed between each of the electrode support portions 71 and the vibrator 70.

Further, among the angular velocity detecting elements 63 to 66,
The angular velocity detecting element 63 and the angular velocity detecting element 65
The supporting beams 69 of the angular velocity detecting elements 63 and 65 are arranged at the front and rear positions so that the extending directions of the supporting beams 69 are parallel to the rotation axis Y-Y. On the other hand, the angular velocity detecting element 6
4 and the angular velocity detecting element 66 are located at the left and right positions of the substrate 62,
The supporting beams 69 of the angular velocity detecting elements 64 and 66 are arranged such that the extending direction of the supporting beams 69 is orthogonal to the rotation axis Y-Y.

Accordingly, the angular velocity detecting device 6 according to the present embodiment
1 indicates that when the angular velocity about the rotation axis XX acts on the angular velocity detecting device 61 in a state where the vibrators 70 of the angular velocity detecting elements 63 to 66 are vibrated in the vertical direction, the angular velocity detecting element 6
Each of the transducers 3 and 65 is displaced in the directions of arrows G1 and G3. However, each transducer 70 of the angular velocity detecting elements 64 and 66
Does not displace.

On the other hand, when the angular velocity about the rotation axis Y-Y acts on the angular velocity detecting device 61 in a state where the vibrators 70 of the angular velocity detecting elements 63 to 66 are vibrated in the vertical direction, the angular velocity detecting elements 64 and 66 Each vibrator 70 is displaced in the directions of arrows G2 and G4. At this time, the angular velocity detecting elements 63 and 65 are not displaced.

As described above, the angular velocity detecting device 61 can detect the angular velocity around the rotation axis XX by the angular velocity detection elements 63 and 65, and the rotation axis Y by the angular velocity detection elements 64 and 66.
-Angular velocity around Y can be detected.

On the other hand, when detecting the angular velocity around the rotation axis Y-Y, each support beam 69 is bent due to the change of the ambient temperature of the angular velocity detecting device 61 or the like, and each vibrator 70 is deformed or deformed. A position shift may occur, or a rotation axis on which the angular velocity actually acts on the angular velocity detection device 61 may shift. In such a case, the rotational axis Y'-
The extension direction (XX direction) of the support beams 69 of the angular velocity detecting elements 64 and 66 is not orthogonal to Y ′, and the vibrators 70 of the angular velocity detecting elements 64 and 66 are moved in the directions of arrows G2 and G4 by Coriolis force. To be displaced.

The amount of displacement of each of the vibrators 70 of the angular velocity detecting elements 64 and 66 increases correspondingly if the influence of the ambient temperature or the degree of axis deviation of the rotational axis Y′-Y ′ which is displaced is large. . Therefore, by detecting the displacement of each transducer 70 of the angular velocity detecting elements 64 and 66 as a change in capacitance by each detection electrode 71, data (variable) corresponding to the magnitude of the axis deviation can be obtained.

Further, as the angular velocity detecting device 61, the same one as the angular velocity detecting circuit (see FIG. 4) of the first embodiment is used.

The angular velocity detecting device 61 according to the present embodiment has the above-described configuration. Next, the overall operation will be described.

First, the oscillating circuit 51 and the phase setting circuit 52 cause the vibration drive signal W having a different phase by 90 degrees, respectively.
When 1, W2, W3, and W4 are applied to the vibration generating electrodes of the angular velocity detecting elements 63 to 66, the vibrators 70 vibrate in a direction orthogonal to the substrate 62 with a phase difference of 90 degrees. Then, when an angular velocity around the rotation axis Y-Y acts on the angular velocity detecting device 61 in a state where each of the vibrators 70 is vibrated, each of the vibrators 7 of the angular velocity detecting elements 63 and 65.
0 is displaced in the directions of arrows G1 and G3 by Coriolis force.

Further, the angular velocity detecting device 61 may be caused by the bending of each support beam 69 or the deformation or displacement of each vibrator 70 due to the influence of a change in the ambient temperature or the like. When the rotation axis on which the angular velocity has actually acted on the device 61 is displaced, the vibrators 70 of the angular velocity detecting elements 64 and 66 are displaced in the directions of arrows G2 and G4 by Coriolis force.

The displacement of each transducer 70 of the angular velocity detecting elements 63 to 66 is detected by each detection electrode 72 as a capacitance change, and a detection signal is taken out and output to each amplifier circuit 53. The detection signal is operated and amplified by each amplifier circuit 53,
The third phase detection circuit 54 and the arithmetic processing circuit 55
An arithmetic operation based on the same method as that of the embodiment is performed to remove an angular velocity detection error due to a change in the ambient temperature of the angular velocity detection device 61 and an angular velocity detection error due to an axis deviation, and to output an angular velocity output signal R corresponding to a true angular velocity. Is output from the arithmetic processing circuit 55.

Thus, as shown in the present embodiment, the four angular velocity detecting elements 63 to 66 may be radially arranged at intervals of 90 degrees about the center point Q as in the first embodiment. Similar to the angular velocity detecting device 31 described above, similar effects such as improving the detection accuracy of each angular velocity around two axes can be obtained.

In each of the above embodiments, each oscillator 39
(70) is converted to the substrate 32 (6
Although it has been described that the vibrator is vibrated in a direction orthogonal to 2), the present invention is not limited to this.
(70) is converted to the substrate 32 by the detection electrodes 42 (72).
It is good also as a structure which vibrates in parallel with (62).

In this case, for example, each vibrator 70 of the angular velocity detecting device 31 according to the first embodiment is replaced by arrows E1, E1 in FIG.
Vibration is performed in the directions of E2, E3, and E4. In this state, when an angular velocity around the rotation axis Y-Y acts, the vibrators 70 of the angular velocity detecting elements 33 and 34 are caused by Coriolis force.
It is displaced in the direction of arrow E5 in FIG. The angular velocity can be obtained by detecting this displacement.

In each of the above embodiments, each vibrator 39
Although (70) has been described as being vibrated using electrostatic force by the vibration generating electrode 40, the present invention is not limited to this, and it may be vibrated by a piezoelectric method, a magnetic method, or the like. In each of the above embodiments, the displacement of each oscillator 39 (70) is detected as a change in capacitance by the detection electrode 42 (72). However, each oscillator 39 (70) is detected by a piezoelectric method, a magnetic method, or the like. 39 (70) may be detected.

Further, in each of the above embodiments, the vibration generating electrode 40 is formed as a thin film on the substrate 32 (62). However, the present invention is not limited to this. For example, impurities such as Pb and Sb are added to the substrate 32 (62). 32 (62) may be formed to have conductivity by doping the surface at high density.

[0103]

As described in detail above, according to the first aspect of the present invention, four angular velocity detecting elements are arranged on a single substrate with one point as a center, and the vibration of each angular velocity detecting element is set. Since the vibrators are configured to vibrate each vibrator at different phases by the vibration generating means, each vibrator of the two angular velocity detecting elements having the support beams arranged in parallel with the rotation axis is displaced by Coriolis force, and The vibrators of the two angular velocity detecting elements having the support beams arranged in parallel with the rotation axis of the above are not displaced by Coriolis force. Further, when the angular velocity acts on the other rotation axis, each vibrator of the two angular velocity detection elements having the support beams arranged in parallel to this rotation axis is displaced by Coriolis force, and Each vibrator of the two angular velocity detecting elements having the support beam arranged parallel to the axis is not displaced by Coriolis force.

Thus, when the angular velocity acts on one of the rotation axes, or when the angular velocity acts on the other rotation axis, the angular velocity detection having the support beams arranged in parallel with the respective rotation axes is performed. The transducers of the elements are less likely to buffer each other, and crosstalk can be reduced. As a result, it is possible to configure a two-axis-compatible angular velocity detecting device with improved angular velocity detection accuracy.

According to the second aspect of the present invention, the vibration generating means of each speed detecting element is configured to vibrate each vibrator in a different phase, so that the vibrations of each vibrator do not interfere with each other. Crosstalk is suppressed, and highly accurate angular velocity detection can be performed.

[Brief description of the drawings]

FIG. 1 is a plan view showing an angular velocity detecting device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken in the direction of arrows II-II in FIG.

FIG. 3 is a plan view showing an arrangement relationship of each angular velocity detecting element when a rotation axis is shifted in the angular velocity detecting device according to the first embodiment.

FIG. 4 is a block circuit diagram showing an angular velocity detection circuit of the angular velocity detection device according to the first embodiment.

FIG. 5 is a plan view showing an angular velocity detecting device according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a conventional angular velocity detecting device.

FIG. 7 is a perspective view showing an angular velocity detecting device according to another related art.

[Explanation of symbols]

31, 61 Angular velocity detecting device 32, 62 Substrate 33, 34, 35, 36, 63, 64, 65, 66 Angular velocity detecting element 37, 67, 68 Supporting part 38, 69 Supporting beam 39, 70 Vibrator 40 Vibration generating electrode (Vibration generating means) 42, 72 Detection electrode (displacement detecting means)

Claims (2)

[Claims] 1. Four angular velocity detecting elements are arranged on a single substrate so as to be symmetrical with respect to one point as a center, and around two rotation axes orthogonal to each other and parallel to the substrate. An angular velocity detecting device that detects an angular velocity acting on each of the angular velocity detecting elements, wherein each of the angular velocity detecting elements includes a support portion fixedly attached to the substrate, a base end side provided on the support portion, and a distal end side relative to the substrate. A support beam extending in a parallel direction, a vibrator supported on a distal end side of the support beam in a state separated from the substrate, and displaceable in a direction parallel to and perpendicular to the substrate; A vibration generating means for vibrating in the vibration direction, and an angular velocity about a rotation axis parallel to the substrate acting on the substrate in a state where the vibrator is vibrated by the vibration generating means. The vibrator has its vibration direction Displacement detecting means for detecting displacement in different constant displacement directions, wherein two of the four angular velocity detecting elements are arranged so that their support beams are orthogonal to the one rotation axis. And the other two angular velocity detecting elements are arranged so that their support beams are orthogonal to the other rotational axis, and one angular velocity is detected. An angular velocity detecting device configured to detect an angular velocity acting around an axis. 2. The angular velocity detecting device according to claim 1, wherein the vibration generating means of each angular velocity detecting element vibrates each vibrator at a different phase.