JP2007292743A - Tuning fork type vibration gyro - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tuning fork type vibration gyro capable of self-diagnosis of abnormality from various viewpoints. <P>SOLUTION: Electrodes 34<SB>1</SB>, 34<SB>2</SB>, 35<SB>1</SB>, 35<SB>2</SB>(base side; 37<SB>1</SB>, 37<SB>2</SB>, 38<SB>1</SB>, 38<SB>2</SB>) for detecting in-plane vibration (vibration in the parallel direction to a base surface) and out-of-plane vibration (vibration in the vertical direction to the base surface) of driving legs 12<SB>1</SB>, 12<SB>2</SB>by a capacitance change are formed on opposite surfaces of the driving legs 12<SB>1</SB>, 12<SB>2</SB>and a base, and electrodes 36<SB>1</SB>, 36<SB>2</SB>(base side; 39<SB>1</SB>, 39<SB>2</SB>) for detecting out-of-plane vibration of detection legs 13<SB>1</SB>, 13<SB>2</SB>by a capacitance change are formed separately from piezoelectric detection electrodes 32, 33 on opposite surfaces of the detection legs 13<SB>1</SB>, 13<SB>2</SB>and the base. A self-diagnosis circuit performs abnormality diagnosis by using each detection voltage detected by each capacitance change of the electrodes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tuning fork type vibration gyro provided with a vibrator made of a piezoelectric material, and more particularly to a tuning fork type vibration gyro having a function of self-diagnosis of an abnormality such as a failure.

The vibration gyro utilizes the fact that when the angular velocity is input to the vibrator, the vibration in the direction orthogonal to the driving vibration direction is generated by the Coriolis force. By detecting this vibration electrically, the input angular velocity is detected. ing.
The vibrator is made of, for example, a piezoelectric single crystal material, and a drive electrode that supplies a drive signal for exciting (resonance driving) the vibrator and a detection electrode for detecting vibration due to Coriolis force are arranged on the vibrator.
The vibrator has various shapes such as a simple columnar shape or a tuning fork shape. Patent Document 1 discloses a pair of drive legs and a pair of detection legs from opposite side surfaces of the body portion having a rectangular plate shape. And a tuning-fork type vibrator having a non-excitation drive leg between a pair of drive legs and a non-detection detection leg between a pair of detection legs.

On the other hand, this type of vibrating gyroscope is also used in the field of consumer use such as car navigation systems, and has been used in various fields. There is an increasing demand for a vibrating gyroscope having a function.
Patent Document 2 describes one configuration of a vibration gyro having such a self-diagnosis function. In this example, detection voltages output from a pair of detection electrodes are added, and the addition voltage and a constant voltage circuit output the addition. The abnormality diagnosis is performed by comparing with a constant voltage.
JP 2001-255152 A Japanese Patent Laid-Open No. 11-51655

However, in the self-diagnosis circuit described in Patent Literature 2, only when the disconnection or the like occurs and the detection voltage output from the detection electrode becomes 0, or when the detection voltage becomes very close to 0, An abnormality can be diagnosed. For example, if the detected voltage is halfway due to some failure (break, crack, electrode peeling, etc.), the abnormality cannot be diagnosed. In that respect, the performance was not sufficient.
The object of the present invention is to solve the conventional drawbacks, and is not limited to an abnormality in which the detection voltage from the detection electrode is 0, and even when the output is halfway due to the abnormality, an abnormality can be diagnosed. The object is to provide a tuning-fork type vibration gyro capable of diagnosing abnormalities from various viewpoints.

According to the first aspect of the present invention, the vibrator formed of the plate-like piezoelectric body is mounted on the base via the support portion with its plate surface parallel to the base surface, and the vibrator is supported by the support portion. And a pair of drive legs and a pair of detection legs protruding in opposite directions from opposite side surfaces of the body part, the pair of drive legs being parallel to the base surface. A tuning-fork type vibration gyro, in which drive electrodes for in-plane vibration in the direction are formed, and detection electrodes for detecting out-of-plane vibration in the direction perpendicular to the base surface of the detection legs are formed on the pair of detection legs, respectively. The electrodes for detecting the in-plane vibration of the drive legs and the out-of-plane vibration in the direction perpendicular to the base surface are detected on the opposing surfaces of the pair of drive legs and the base, respectively, A pair of detection legs and base An electrode for detecting the out-of-plane vibration of the detection legs by the change in capacitance is formed on the surface facing each other, and each detection voltage detected by the change in capacitance of these electrodes is abnormal. A self-diagnosis circuit for performing diagnosis is provided.

  In the invention of claim 2, in the invention of claim 1, the self-diagnosis circuit diagnoses an abnormality of in-plane vibration of the pair of drive legs, a circuit diagnoses an abnormality of the out-of-plane vibration of the pair of drive legs, A circuit for diagnosing out-of-plane vibration of the pair of detection legs and an abnormality in the gyro output.

According to a third aspect of the present invention, in the second aspect of the invention, the circuit for diagnosing an abnormality in the in-plane vibration of the pair of drive legs detects two in-plane vibrations of the pair of drive legs based on a capacitance change. adding means for adding an output of the rectified and smoothed the output of the adding means, means for outputting a comparison result by comparing the constant voltage V _1, a subtraction means for subtracting the two detection voltages, and an output thereof is rectified and smoothed output of the subtraction means, is intended to comprise a means for outputting to a comparison result compared with the predetermined voltage V _2.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the circuit for diagnosing an abnormality in the out-of-plane vibration of the pair of drive legs detects two out-of-plane vibrations of the pair of drive legs based on a capacitance change. comparison adding means for adding, that the drive signal input to output to the drive electrodes of the adding means synchronously detects the phase adjustment signal, an output obtained by rectifying and smoothing the detection output, a constant voltage V ₃ a Then, a means for outputting a comparison result, a subtracting means for subtracting the two detected voltages, an output of the subtracting means synchronously detected by the phase-adjusted signal, an output obtained by rectifying and smoothing the detected output, It is intended to comprise a means for outputting a comparison result by comparing the constant voltage V _4.

  According to a fifth aspect of the present invention, in the second aspect of the present invention, the circuit for diagnosing out-of-plane vibrations of the pair of detection legs and an abnormality in the gyro output detects the out-of-plane vibrations of the pair of drive legs based on capacitance changes. First subtracting means for subtracting two detection voltages, synchronously detecting the output of the first subtracting means with a signal obtained by adjusting the phase of the drive signal input to the drive electrode, and rectifying and smoothing the detected output; Means for adjusting the gain to obtain a first output; second subtraction means for subtracting two detection voltages obtained by detecting the out-of-plane vibrations of the pair of detection legs by capacitance change; and the second subtraction means. Is detected synchronously by the phase-adjusted signal, the detected output is rectified and smoothed, and the gain is adjusted to obtain the second output, and the output of the second subtracting means is synchronously detected by the drive signal. , That The detection output obtained by rectifying and smoothing the detection output, further adjusting the gain to obtain the third output, and subtracting the two detection voltages respectively extracted from the detection electrodes of the pair of detection legs is phase-adjusted. A means for outputting a comparison result by comparing the first output with the fourth output obtained by synchronously detecting the signal and rectifying and smoothing the detected output, and comparing the second output with the fourth output Then, a means for outputting the comparison result and the gyro output obtained by synchronously detecting the detection signal with the drive signal and rectifying and smoothing the detection output are compared with the third output to output the comparison result. Means.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the electrode for detecting in-plane vibration of the drive leg has a comb-teeth shape.

  According to the seventh aspect of the present invention, a vibrator formed of a plate-like piezoelectric body is mounted on a base via a support portion with its plate surface parallel to the base surface, and the vibrator is supported by the support portion. And a pair of drive legs and a pair of detection legs protruding in opposite directions from opposite side surfaces of the body part, the pair of drive legs being parallel to the base surface. A tuning-fork type vibration gyro, in which drive electrodes for in-plane vibration in the direction are formed, and detection electrodes for detecting out-of-plane vibration in the direction perpendicular to the base surface of the detection legs are formed on the pair of detection legs, respectively. In the body part, electrodes for detecting out-of-plane vibration in the direction perpendicular to the base surface of the shoulder part by the piezoelectric effect are formed on both shoulder parts on the driving leg side and both shoulder parts on the detection leg side in the body part, respectively. Be detected It is configured having a self-diagnosis circuit for performing abnormality diagnosis by using the detected voltage.

  In the invention of claim 8, in the invention of claim 7, the self-diagnostic circuit includes a circuit for diagnosing an abnormality in the out-of-plane vibration of the pair of drive legs and a circuit for diagnosing an abnormality in the out-of-plane vibration of the pair of detection legs. It is supposed to be prepared.

In the ninth aspect of the invention, in the eighth aspect of the invention, the circuit for diagnosing the abnormality of the out-of-plane vibration of the pair of driving legs subtracts two detection voltages respectively detecting the out-of-plane vibrations of both shoulders on the driving leg side. subtracting means for its drive signal input to output to the drive electrode of the subtraction means synchronously detects the phase adjustment signal, compares the output obtained by rectifying, smoothing the detection output, a constant voltage V ₁₁ A means for outputting a comparison result, an adding means for adding the two detected voltages, an output obtained by synchronously detecting the output of the adding means by the phase-adjusted signal, and rectifying and smoothing the detected output; and a constant voltage And means for comparing V _12H and V _12L with each other and outputting a comparison result.

In the invention of claim 10, in the invention of claim 8, the circuit for diagnosing the abnormality of the out-of-plane vibration of the pair of detection legs subtracts two detection voltages respectively detecting the out-of-plane vibration of both shoulders on the detection leg side. subtracting means for its drive signal input to output to the drive electrode of the subtraction means synchronously detects the phase adjustment signal, compares the output obtained by rectifying, smoothing the detection output, a constant voltage V ₁₃ A means for outputting a comparison result, an adding means for adding the two detected voltages, an output obtained by synchronously detecting the output of the adding means by the phase-adjusted signal, and rectifying and smoothing the detected output; and a constant voltage by comparing the V ₁₄ it is assumed and means for outputting the comparison result.

  According to the invention of claim 11, the vibrator formed of the plate-like piezoelectric body is mounted on the base via the support portion, and the plate surface thereof is parallel to the base surface, and the vibrator is supported by the support portion. And a pair of drive legs and a pair of detection legs protruding in opposite directions from opposite side surfaces of the body part, the pair of drive legs being parallel to the base surface. A tuning-fork type vibration gyro, in which drive electrodes for in-plane vibration in the direction are formed, and detection electrodes for detecting out-of-plane vibration in the direction perpendicular to the base surface of the detection legs are formed on the pair of detection legs, respectively. In the body part, both the shoulders on the driving leg side and the shoulders on the detection leg side and the base face each other on the opposite surfaces of the base part of the shoulder part due to a change in capacitance. Each electrode for detection Formed, it is configured having a self-diagnosis circuit for performing abnormality diagnosis by using each detection voltage detected by the capacitance change of the electrodes.

  In a twelfth aspect of the invention according to the eleventh aspect of the invention, the self-diagnostic circuit includes a circuit for diagnosing an abnormality in the out-of-plane vibration of the pair of drive legs and a circuit for diagnosing the abnormality in the out-of-plane vibration of the pair of detection legs. It is supposed to be prepared.

According to a thirteenth aspect of the present invention, in the twelfth aspect of the invention, the circuit for diagnosing an abnormality in the out-of-plane vibrations of the pair of driving legs detects the out-of-plane vibrations of both shoulders on the driving leg side by changing the capacitance. Subtracting means for subtracting two detection voltages, the output of the subtracting means is synchronously detected by a signal obtained by adjusting the phase of the drive signal inputted to the drive electrode, the output obtained by rectifying and smoothing the detected output, and the constant voltage V ₂₁ And a means for outputting a comparison result, an adding means for adding the two detection voltages, and synchronously detecting the output of the adding means with the phase-adjusted signal, and rectifying and smoothing the detection output. A means for comparing the output with each of the constant voltages V _22H and V _22L and outputting a comparison result is provided.

According to a fourteenth aspect of the present invention, in the twelfth aspect of the invention, the circuit for diagnosing the abnormality of the out-of-plane vibrations of the pair of detection legs detects the out-of-plane vibrations of both shoulders on the detection leg side by changing the capacitance. Subtracting means for subtracting two detection voltages, the output of the subtracting means is synchronously detected by a signal obtained by adjusting the phase of the drive signal inputted to the drive electrode, the output obtained by rectifying and smoothing the detected output, and the constant voltage V ₂₃ And a means for outputting a comparison result, an adding means for adding the two detection voltages, and synchronously detecting the output of the adding means with the phase-adjusted signal, and rectifying and smoothing the detection output. A means for comparing the output with the constant voltage V ₂₄ and outputting a comparison result is provided.

  According to the present invention, for example, when a vibration state abnormality occurs in the drive leg or the detection leg due to a failure or the like, the abnormality diagnosis can be performed even if the abnormality is slight, and thus a tuning fork type having excellent detection accuracy. A vibrating gyro can be obtained.

Embodiments of the present invention will be described with reference to the drawings.
[Example 1]
FIG. 1 shows a mounting structure of a vibrator in a first embodiment of a tuning fork type vibration gyro according to the present invention, FIG. 2 shows the arrangement of various electrodes with respect to the vibrator, and FIGS. The electrode details for detecting a vibration by the change of an electrostatic capacitance are shown. FIGS. 5 and 6 show a self-diagnosis circuit provided in the tuning-fork type vibration gyro according to the first embodiment of the present invention. First, the structure / mounting structure of the vibrator and the electrode arrangement will be described with reference to FIGS.

The vibrator 10 is formed of a plate-like piezoelectric body, and includes a body portion 11, a pair of drive legs 12 ₁ and 12 ₂ and a pair of detection legs 13 ₁ and 13 ₂ as shown in FIG. It has become those with a non-excitation driving tines 12 ₃ and the non-detection detection tines 13 _3. As the piezoelectric material, for example, a piezoelectric single crystal material such as quartz, langasite, or lithium niobate is used.

Body portion 11 is a rectangular plate, a pair of drive legs ₁₂ 1, 12 ₂ and parasitic driving tines 12 ₃ from opposite sides thereof to each other, a pair of detection legs ₁₃ 1, 13 ₂ and the non-detection detection tines 13 ₃ project in opposite directions. These driving feet ₁₂ 1, 12 _2, parasitic drive legs 12 _3, the detection tines ₁₃ 1, 13 ₂ and the non-detection detection tines 13 ₃ is a prismatic, parasitic drive legs 12 ₃ and the non-detection detection tine 13 ₃ They are positioned between the pair of drive legs 12 ₁ and 12 _{2 and} between the pair of detection legs 13 ₁ and 13 ₂ , respectively.

The vibrator 10 is mounted on the base 22 via the support portion 21, and its plate surface is parallel to the base surface 22 a (the upper surface of the base 22). The support portion 21 has a thin columnar shape as shown in FIG. 1B, is located at the center of gravity of the vibrator 10, and is joined and fixed to the base 22 and the body portion 11, respectively. Incidentally, the parasitic driving tines 12 ₃ and the non-detection detection tine 13 ₃ is used for mass balance of the detection tines ₁₃ 1, 13 ₂ side driving legs ₁₂ 1, 12 ₂ side with respect to the body portion 11.

  In this example, a base of a 14-pin standard package is used as the base 22, and reference numeral 23 in FIG. In FIG. 1A, the illustration of the cover of the package is omitted, and various electrodes formed on the vibrator 10, bonding wires connecting them to the pins 23, patterns on the base 22, and the like are shown. Is also omitted.

Next, the electrode arrangement with respect to the vibrator 10 will be described.
2A is a view of the vibrator 10 as viewed from the upper surface 10a side in FIG. 1A, that is, from the side opposite to the base 22, and the driving legs 12 ₁ and 12 ₂ are shown in FIG. 2B. As shown, the drive electrodes 31 (31a, 31b) are formed on the four surfaces of the four surfaces in the center in the width direction. The drive electrodes 31a and 31b have the same polarity, and a drive signal is supplied between the drive electrodes 31a and 31b. Driving electrodes 31a, 31b are formed on the drive legs ₁₂ 1, 12 ₂ of the base end side.

On the other hand, the detection tines 13 ₁ and 13 ₂ respectively detecting electrodes 32 on the upper surface 10a perpendicular sides in (32a, 32 b) and 33 (33a, 33b) is in the width direction at both ends as shown in FIG. 2 (c) Is located. The detection electrodes 32a, 32b, 33a and 33b have the same polarity, that is, the detection electrodes positioned in the diagonal direction have the same polarity. Detection electrodes 32 and 33 are formed on the detection tines ₁₃ 1, 13 ₂ of the base end side, the detection voltage to detect the vibration from these detection electrodes 32 and 33 due to the Coriolis force of the detection leg ₁₃ 1, 13 ₂ is taken out. The arrangement of the drive electrode 31 and the detection electrodes 32 and 33 in FIG. 2 shows an arrangement example when the vibrator 10 is formed using a Z-cut piezoelectric single crystal. When formed using a cut piezoelectric single crystal, the arrangement of the drive electrode and the detection electrode is different from the arrangement of FIG. 2, for example, in FIGS. 15 to 17 of the aforementioned Patent Document 1 (Japanese Patent Laid-Open No. 2001-255152). The arrangement is as shown.

In this example, in addition to the drive electrode 31 and the detection electrodes 32 and 33, capacitance detection electrodes are further provided on the surfaces of the drive legs 12 ₁ and 12 ₂ and the detection legs 13 ₁ and 13 ₂ facing the base surfaces 22a. Is formed.

Driving tines ₁₂ 1, electrodes ₃₄ 1 forming the comb-teeth shape in 12 _2, 34 ₂ is formed on the distal end side, respectively, further electrodes forming a square shape between the electrodes ₃₄ 1, 34 ₂ and the drive electrode 31 3
5 ₁ and 35 ₂ are formed. On the other hand, the detection leg ₁₃ 1, 13 electrodes ₃₆ 1 forming a rectangular shape in _2, 36 ₂ are formed on the distal end side, respectively. Electrodes ₃₄ 1, 34 ₂ of the comb teeth are parallel to the stretching and the stretching direction of the driving tines ₁₂ 1, 12 _2, are arranged in the width direction of the driving tines ₁₂ 1, 12 _2. For example, in FIG. 2A, the electrodes 34 ₁ and 34 ₂ are shown as having four comb teeth. In addition, illustration of the connection part which connects these four comb teeth at the one end side is abbreviate | omitted.

Electrodes facing the electrodes 34 ₁ , 34 ₂ , 35 ₁ , 35 ₂ , 36 ₁ , and 36 ₂ are formed on the base surface 22a (the upper surface of the base 22). 3 and 4 have the meanings indicated in detail, similar to the electrodes ₃₄ 1, 34 ₂ and the counter electrodes ₃₇ 1, 37 ₂ electrodes ₃₄ 1, 34 _2, comb as shown in FIG. 3 (c) is intended to form a tooth shape, the electrodes ₃₈ 1, 38 ₂ facing the electrode ₃₅ 1, 35 ₂ is wider than the electrode ₃₅ 1, 35 ₂ as shown is a rectangular shape in FIG. 3 (b) Yes. Further, the electrodes 39 ₁ and 39 ₂ facing the electrodes 36 ₁ and 36 ₂ have a rectangular shape and are wider than the electrodes 36 ₁ and 36 ₂ as shown in FIG. 4B.

In the configuration as described above, by supplying a drive signal to the drive electrode 31 (31a, 31b), the pair of drive legs 12 ₁ , 12 ₂ are excited, and in a direction parallel to the base surface 22a, that is, FIG. In-plane vibrations in opposite phases to each other in the X direction shown in FIG. When an angular velocity in the drive leg ₁₂ 1, 12 ₂ in the stretching direction or Y-axis in this state is inputted, the base surface 22a and the direction perpendicular to the drive leg ₁₂ 1, 12 ₂ by the Coriolis force, that is, out-of-plane vibration in the Z-direction As a result, the drive legs 12 ₁ and 12 ₂ vibrate out of plane in opposite phases. The plane vibration (vibration in the Z-direction) is transmitted to the detection tine ₁₃ 1, 13 ₂ via the body portion 11, thereby detecting the legs ₁₃ 1, 13 opposite phases of the out-of-plane vibration to the ₂ (the vibration in the Z-direction) Will occur. In this way, the detection legs 13 ₁ and 13 ₂ vibrate out of plane to excite a voltage on the detection electrodes 32 and 33, and the input angular velocity can be detected by detecting this voltage.

Although the detection leg ₁₃ 1, 13 ₂ plane vibration is generated in accordance with the plane vibration of the driving tines ₁₂ 1, 12 _2, the driving legs ₁₂ 1, 12 ₂ of the surface vibration (vibration in the X-direction) is transmitted is prevented in that direction detection tine ₁₃ 1 by the rigidity of the (X-direction), 13 ₂ of the body portion 11, i.e. (vibration in the X-direction) detected legs ₁₃ 1, 13 ₂ plane vibration in does not occur It has become a thing.

While out-of-plane vibration of the detection leg 13 _1, 13 ₂ corresponding to the input angular rate is detected by the detection voltage is taken out from the detection electrodes 32 and 33 as described above, in addition to this, in this example, by a change in capacitance it can also be able to detect the out-of-plane vibration of the detection leg 13 _1, 13 _2, detected by the further drive legs 12 _1, 12 ₂ in-plane vibration and out-of-plane vibrations changes in capacitance.

That is, the out-of-plane vibrations of the detection legs 13 ₁ and 13 ₂ can be detected by the change in capacitance between the electrodes 36 ₁ and 39 ₁ and the electrodes 36 ₂ and 39 ₂ arranged to face each other. 12 _1, 12 ₂ in-plane vibrations can be detected respectively by mutually oppositely disposed electrodes ₃₄ 1, 37 ₁ and between the electrodes ₃₄ 2, 37 of the electrostatic capacitance between the _second change. Also, out-of-plane vibration of the driving tines ₁₂ 1, 12 ₂ can be detected by each other oppositely disposed electrodes ₃₅ 1, 38 ₁ and between the electrodes ₃₅ 2, 38 of the capacitance between the _second change.

That is, in this example can detect the pair of drive legs 12 _1, 12 ₂ of the surface vibration and out-of-plane vibration by capacitance change further pair of detection legs 13 _1, 13 ₂ of plane vibration detection Each of these capacitance changes can be detected as a voltage change, and various abnormality diagnoses can be performed by using the detected voltage.

  Hereinafter, various abnormality diagnosis will be described with reference to the self-diagnosis circuits shown in FIGS. In addition, the electrostatic capacitance change of each counter electrode shall be detected as a voltage change from the electrode formed in the base surface 22a.

<Abnormal diagnosis of in-plane vibration of driving leg>
Electrodes ₃₇ 1, 37 ₂ of the capacitance change detecting a pair of driving legs ₁₂ 1, 12 ₂ of the surface vibration is detected as the respective voltage change by the detection circuits 41 and 42 as shown in FIG. 5, these Two detection voltages output from the detection circuits 41 and 42 are input to the adding means 43 and added. The output of the summing means 43 is rectified and smoothed by the rectifier circuit 44 and a low pass filter 45, the output S _1. The comparator 46 receives the constant voltage V ₁ and the output S ₁ output from the constant voltage circuit 47.

Since the driving legs 12 ₁ and 12 ₂ vibrate in plane in opposite phases, the output S ₁ becomes 0 if the in-plane vibrations of the driving legs 12 ₁ and 12 ₂ are perfectly balanced. However, in reality, such an ideal state cannot be obtained, and a certain degree of imbalance occurs. Therefore, the constant voltage V ₁ is set to a value (maximum allowable value) at which the output S ₁ can be in a normal operation state. The comparator 46 compares the output S ₁ with the constant voltage V ₁ and outputs “1” as the comparison result when V ₁ <S ₁ . That is, the output A of the comparator 46 is “0” when normal (when V ₁ ≧ S ₁ ), and becomes “1” when the balance is abnormal.

The two detection voltages output from the detection circuits 41 and 42 are input to the subtraction means 51 and subtracted. Output of the subtraction means 51 is rectified and smoothed by the rectifier circuit 52 and a low pass filter 53, the output S _2. A constant voltage V ₂ and an output S ₂ output from the constant voltage circuit 55 are input to the comparator 54.

The output S ₂ corresponds to the amplitude of the in-plane vibration of the drive legs 12 ₁ , 12 ₂ , that is, represents the magnitude of the amplitude, and here is constant at the minimum value of the output S ₂ that is determined to be a normal operation state. to set the voltage _{V 2.} The comparator 54 compares the output S ₂ with the constant voltage V _2, and outputs “1” as the comparison result when V ₂ > S ₂ . The output B of the comparator 54 is “0” when normal (when V ₂ ≦ S ₂ ), and is “1” when the amplitude is abnormal (small amplitude abnormality).

<Abnormal diagnosis of drive leg out-of-plane vibration>
Electrodes ₃₈ 1, 38 ₂ of the capacitance change detecting a pair of plane vibration of the driving tines ₁₂ 1, 12 ₂ are detected respectively as voltage change by the detection circuits 61 and 62 as shown in FIG. 6, these Two detection voltages output from the detection circuits 61 and 62 are input to the adding means 63 and added. The output of the adding means 63 is input to the synchronous detection circuit 64. The synchronous detection circuit 64 synchronously detects the signal input from the adding means 63 by using a signal obtained by adjusting the phase by delaying the phase of the drive signal output from the drive circuit 71 by 90 degrees. Although not shown in FIG. 6, the drive signal is input to the drive electrodes 31 (31a, 31b), and thereby the pair of drive legs 12 ₁ and 12 ₂ are excited. In FIG. 6, reference numeral 72 denotes a phase shift circuit that adjusts the phase of the drive signal and delays it by 90 degrees.

Detection output of the synchronous detection circuit 64 is rectified and smoothed by the rectifier circuit 65 and a low pass filter 66, the output S _3. The comparator 67 receives the constant voltage V ₃ and the output S ₃ output from the constant voltage circuit 68.

When the angular velocity is input, the driving legs 12 ₁ and 12 ₂ vibrate out of plane in opposite phases. On the other hand, when the angular velocity is not inputted, a certain amount of out-of-plane vibration is generated in the driving legs 12 ₁ and 12 ₂ in the same phase due to the influence of in-plane vibration due to excitation. The output S ₃ corresponds to the amplitude of the out-of-plane vibration of the case, that is, it represents the magnitude of the amplitude. Accordingly, the constant voltage V ₃ is set to the maximum value of the output S ₃ that is determined to be a normal operation state when the angular velocity is not input. The comparator 67 compares the output S ₃ with the constant voltage V ₃ and outputs “1” as the comparison result when V ₃ <S ₃ . The output C of the comparator 67 is “0” when normal (when V ₃ ≧ S ₃ ), and becomes “1” when the amplitude is abnormal (abnormal amplitude abnormality).

The driving legs 12 _1, 12 the amplitude of the _second plane vibration atmospheric abnormalities be those generated basically driven legs 12 _1, 12 ₂ of the amplitude large abnormally corresponding plane vibration, in other words the comparator It can be said that the output C of 67 represents a large amplitude abnormality of the in-plane vibration of the drive legs 12 ₁ and 12 ₂ . Therefore, both the small and large abnormalities of the in-plane vibrations of the drive legs 12 ₁ and 12 ₂ can be diagnosed by the output C of the comparator 67 and the output B of the comparator 54 described above.

  From this point, for example, a large amplitude abnormality may be determined based on the output B of the comparator 54, and a small amplitude abnormality may be determined based on the output C of the comparator 67.

On the other hand, the two detection voltages output from the detection circuits 61 and 62 are input to the subtraction means 81 and subtracted. The output of the subtracting means 81 is input to the synchronous detection circuit 82, and the synchronous detection circuit 82 synchronously detects the signal input from the subtraction means 81 by the signal output from the phase shift circuit 72, as in the above-described synchronous detection circuit 64. . Detection output of the synchronous detection circuit 82 is rectified and smoothed by the rectifier circuit 83 and a low pass filter 84, the output S _4. A constant voltage V ₄ and an output S ₄ output from the constant voltage circuit 86 are input to the comparator 85.

The output S ₄ is zero ideally during angular missing. However, if there is an imbalance in the out-of-plane vibrations in the same phase of the driving legs 12 ₁ and 12 ₂ , the value becomes a certain value, and thus the output S ₄ can be in a normal operating state (a maximum allowable value) at a constant voltage. setting the V _4. The comparator 85 compares the output S ₄ with the constant voltage V _4, and outputs “1” as a comparison result when V ₄ <S ₄ . The output D of the comparator 85 is “0” when normal (when V ₄ ≧ S ₄ ), and becomes “1” when the balance is abnormal.

<Abnormal diagnosis of out-of-plane vibration of detection legs and gyro output>
A pair of detection legs ₁₃ 1, 13 electrodes ₃₉ 1 for detecting a _second plane vibration, 39 ₂ of the capacitance change is detected as a respective voltage change by the detection circuit 91, 92 as shown in FIG. 6, these Two detection voltages output from the detection circuits 91 and 92 are input to the subtraction means 93 and subtracted. The output of the subtracting means 93 is input to the synchronous detection circuit 94, and the synchronous detection circuit 94 synchronously detects the signal input from the subtracting means 93 by the signal output from the phase shift circuit 72. Detection output of the synchronous detection circuit 94 is rectified and smoothed by the rectifier circuit 95 and a low pass filter 96, the output S ₆ is further gain adjustment by the gain adjusting circuit 97.

The output of the subtracting means 93 is input to the synchronous detection circuit 101, and the synchronous detection circuit 101 synchronously detects the signal input from the subtracting means 93 by the drive signal output from the drive circuit 71. Detection output of the synchronous detection circuit 101 is rectified and smoothed by the rectifier circuit 102 and a low pass filter 103, the output S ₇ are further gain adjustment by the gain adjusting circuit 104.

On the other hand, two detection voltages taken respectively from the detection electrodes 32 and 33 detected by the detection tines 13 _1, 13 ₂ of the piezoelectric effect out-of-plane vibrations are subtracted is inputted to the subtracting means 111, are the detection signal. The detection signal output from the subtracting unit 111 is input to the synchronous detection circuit 112. The synchronous detection circuit 112 performs synchronous detection on the detection signal based on the signal output from the phase shift circuit 72. Detection output of the synchronous detection circuit 112 is rectified and smoothed by the rectifier circuit 113 and a low pass filter 114, the output _{S 8.}

Further, the detection signal output from the subtracting means 111 is input to the synchronous detection circuit 115, and the synchronous detection circuit 115 synchronously detects the detection signal by the drive signal. Detection output of the synchronous detection circuit 115 is rectified and smoothed by the rectifier circuit 116 and a low pass filter 117, it is the output _{S 0.} The output S ₀ is the gyro output (angular velocity output).

In the angular velocity has not been input, in response to the out-of-plane vibration of the same phase of the driving tines 12 _1, 12 _2, also plane vibration of the same phase to the detection leg 13 _1, 13 ₂ (leakage vibration) is generated. In this case, if the out-of-plane vibrations of the detection legs 13 ₁ and 13 ₂ are perfectly balanced, the output S ₆ is zero. However, in practice some imbalance is generated in the detection tine 13 _1, 13 ₂ of the out-of-plane vibration is thus output S ₆ becomes a value corresponding to the imbalance.
Similarly, the detection leg 13 _1, 13 value corresponding to the unbalance of the _second plane vibration output S ₈ in the angular velocity has not been input,.

On the other hand, the output S ₇ corresponds to the gyro output when the angular velocity input detected by the electrostatic capacitance change (angular velocity output).
The outputs S ₆ , S ₇ , S ₈ , S ₀ and the output S ₅ obtained by adjusting the gain of the output S ₄ by the gain adjusting circuit 87 are input to the comparator for comparison. The comparator 88 is input the output _{S 5} and _{S 8,} the comparator 98 outputs _{S 6} and _{S 8} are input. Further, the comparator 105 outputs _{S 7} and _{S 0} are inputted. That is, the comparators 88, 98, and 105 receive the output (displacement (vibration)) detected by the capacitance change and the output detected by the piezoelectric effect, and compare them. The gain adjustment circuits 87, 97, and 104 correct the difference between the capacitance detection efficiency with respect to the displacement and the piezoelectric effect detection efficiency, and the gain adjustment circuits 87, 97 have the same output for the same displacement amount. , 104 perform gain adjustment.

Here, the output detected by the capacitance change is assumed to be more reliable than the output detected by the piezoelectric effect, that is, the abnormality is less likely to occur, and the output detected by the capacitance change is abnormal. Make a diagnosis. One of the reasons that the output detected by the capacitance change is less likely to cause an abnormality is that it can be detected by the electrodes formed on the base surface 22a, that is, the detection legs 13 ₁ and 13. _{When the} detection voltage is taken out from the detection electrodes 32 and 33 formed in FIG. ₂ , a bonding wire is necessary, and an abnormality caused by the disconnection or the like is likely to occur.

The comparator 88 compares the outputs S ₅ and S ₈ and outputs “1” as the comparison result when S ₅ <S ₈ . This is to judge that the case where the detection legs 13 ₁ and 13 ₂ have a large imbalance in the out-of-plane vibration of the driving legs 12 ₁ and 12 ₂ when the angular velocity is not inputted is judged as abnormal. the output E of 88 when _{S 5} ≧ _{S 8} is "0", when the angular velocity has not been input, the detection tines ₁₃ 1, 13 ₂ of plane vibration abnormality (out-of-plane vibration imbalance), and "1" Become.

The comparator 98 compares the outputs S ₆ and S _8, and outputs “1” as the comparison result when S ₆ > S ₈ . This is what determines that the unbalance of the detection tines 13 _1, 13 ₂ of the out-of-plane vibration at the time of the angular velocity not entered, there is an abnormality in the detection by the piezoelectric effect (detection performance), the output F of the comparator 98 S ₆ ≦ when S ₈ is "0", when the piezoelectric detection abnormality becomes "1".

The comparator 105 compares the outputs S ₇ and S _0, and outputs “1” as the comparison result when S ₇ > S ₀ . This is to judge that there is an abnormality in the gyro output S ₀ detected by the piezoelectric effect at the time of angular velocity input. The output G of the comparator 105 is “0” when S ₇ ≦ S ₀ , and the gyro output at the time of angular velocity input. when the output _{S 0} abnormal, set to "1". The abnormality diagnosis by the comparator 105 diagnoses an abnormality that cannot be diagnosed by the comparator 98.

  The outputs A to G of the comparators 46, 54, 67, 85, 88, 98 and 105 described above are input to the OR circuit 48 as shown in FIG. If there is any “1”, “1” is output as the self-diagnosis output. Therefore, the abnormality can be detected by the self-diagnosis output “1”.

Thus, the driving legs 12 _1, 12 ₂ in-plane vibration plane outside vibration and detection legs 13 _1, 13 ₂ of the out-of-plane vibration (leakage vibration Coriolis vibration) the capacitance change, respectively, according to this example By using these detection voltages, as described above, the abnormality diagnosis of the in-plane vibrations (balance, amplitude) of the drive legs 12 ₁ , 12 ₂ , the drive legs 12 ₁ , 12 ₂ of plane vibration (balance, amplitude) abnormality diagnosis, the abnormality diagnosis and an abnormality diagnosis of the gyro output of the out-of-plane vibration of the detection leg 13 _1, 13 ₂ (balance) and (abnormality diagnosis of the piezoelectric detection system and detection circuit) It can be done. Accordingly, various abnormal modes can be diagnosed as compared to the conventional case, and abnormality diagnosis can be performed even when the gyro output is halfway due to a failure or the like.

[Example 2]
In this example, the abnormality detection electrodes are not provided on the drive legs 12 ₁ , 12 ₂ and the detection legs 13 ₁ , 13 ₂ as in the first embodiment, but are provided on the shoulders of the body 11. .
First, the vibration of the shoulder portion of the body portion 11 will be described with reference to FIG.

As shown in FIG. 7A, the pair of drive legs 12 ₁ , 12 ₂ are vibrated in-plane as indicated by arrows e, f by being excited (resonance driven). If the drive legs 12 ₁ , 12 ₂ are balanced, the displacement difference of in-plane vibration of these drive legs 12 ₁ , 12 ₂ becomes 0, and occurs in these drive legs 12 ₁ , 12 ₂ when the angular velocity is not input. The out-of-plane vibration also has the same phase and the same displacement as indicated by arrows g and h. At this time, in accordance with the plane vibration of the driving tines 12 _1, 12 _2, of the body portion 11 drives the leg 12 ₁ on the side where the shoulder portion 11a and the driving legs 12 _second side being protruded is formed projecting Out-of-plane vibration is also generated in the shoulder portion 11b, and the body portion 11 is displaced by vibration as indicated by a two-dot chain line in the drawing. In this case, the out-of-plane vibrations of the shoulder portions 11a and 11b are in phase and displaced in the same manner as the drive legs 12 ₁ and 12 ₂ . At this time, although not shown, the detection leg ₁₃ 1, 13 both shoulders and the detection legs ₁₃ 1 ₂ side, 13 ₂ of the out-of-plane vibration of the body 11 (leakage vibration) similarly has, In other words, they have the same phase and displacement.

On the other hand, for example, the driving legs ₁₂ 1, 12 ₂ some failure or the like occurs and the balance of the two drive legs ₁₂ 1, 12 ₂ is lost, both as indicated by the arrow e ', f' in FIG. 7 (b) displacement difference is generated in the in-plane vibration of the driving tines ₁₂ 1, 12 _2. This displacement difference also causes a displacement difference in the out-of-plane vibration as indicated by arrows g ′ and h ′. Similarly, the displacement difference also occurs in the out-of-plane vibration of both shoulder portions 11a and 11b of the body portion 11. Arise. Further, the detection tines ₁₃ 1, 13 both shoulders and the detection tine ₁₃ 1 ₂ side, 13 displacement difference similarly to the _second plane vibration (leakage vibration) of the body portion 11 occurs.

By this example for detecting a plane vibration generated in the shoulder portion of the body portion 11 as the drive leg 12 _1, 12 ₂ and the detection legs 13 _1, 13 ₂ and performs abnormality diagnosis of plane vibration driving tines ₁₂ 1, 12 ₂ side of the both shoulder portions 11a of the body portion 11 as shown in FIG. 8, 11b and detection legs ₁₃ 1, 13 ₂ side of the both shoulders 11c, to 11d, their shoulders 11a~ Assume that an electrode for detecting the out-of-plane vibration of 11d by the piezoelectric effect is provided.

That is, the shoulder portion 11a is formed with the electrodes 15a-1 and 15a-2 facing each other on the upper and lower surfaces, and the electrode 15b is formed on the side surface, and the other shoulder portions 11b to 11d are similarly formed. Three electrodes 16a-1, 16a-2, 16b and 17a-1, 17a-2, 17b and 18a-1, 18a-2, 18b are formed. In this example, it is assumed that the vibrator 10 is formed using an X-cut piezoelectric single crystal. In FIG. 8, the drive electrode 31 and the detection electrodes 32 and 33 are not shown.
Hereinafter, various abnormality diagnosis in this example will be described with reference to the self-diagnosis circuit shown in FIG.

<Diagnosis of balance abnormality of out-of-plane vibration of driving leg>
The electrodes 15a-1 and 15a-2 provided on the shoulder 11a have the same polarity, and the subtraction means 201 calculates the detection voltage extracted from these electrodes 15a-1 and 15a-2 and the detection voltage extracted from the electrode 15b. To be subtracted (differential output). Similarly, the detection voltage extracted from the electrodes 16a-1 and 16a-2 provided on the shoulder 11b and the detection voltage extracted from the electrode 16b are input to the subtracting means 202 and subtracted.

The two output voltages output from the subtracting means 201 and 202 indicate the out-of-plane vibrations of the shoulder portions 11a and 11b, respectively. The two output voltages are input to the subtracting means 203 and are subtracted. The output of the subtracting means 203 is input to the synchronous detection circuit 204. The synchronous detection circuit 204 synchronously detects the signal input from the subtracting means 203 by a signal (phase shift circuit 72 output signal) obtained by delaying the phase of the drive signal output from the drive circuit 71 by 90 degrees and adjusting the phase. . Detection output of the synchronous detection circuit 204 is rectified and smoothed by the rectifier circuit 205 and a low pass filter 206, the output _{S 11.} The comparator 207 receives the constant voltage V ₁₁ and the output S ₁₁ output from the constant voltage circuit 208.

The output S ₁₁ is zero ideally during angular missing. However, the shoulder portion 11a, the unbalance plane vibration of the same phase of 11b occurs, becomes a certain value, thus the output S ₁₁ can become a normal operating state value constant (maximum acceptable) Voltage V ₁₁ Set. The comparator 207 compares the output S ₁₁ with the constant voltage V _11, and outputs “1” as the comparison result when V ₁₁ <S ₁₁ . The output J of the comparator 207 is “0” when normal (when V ₁₁ ≧ S ₁₁ ), and becomes “1” when the balance is abnormal.

  FIG. 10 is taken out from the electrodes 15a-1, 15a-2, 15b and the electrodes 16a-1, 16a-2, 16b in a state where the out-of-plane vibrations of the shoulder portions 11a, 11b of the body 11 are unbalanced. This is an example of the detected voltage. In the figure, a two-dot chain line indicates one state of displacement (deformation) of both shoulder portions 11a and 11b. Further, the lower / upper side of the detected voltage waveform indicates the time of the lower deformation (state indicated by a two-dot chain line) and the time of the upper deformation.

<Amplitude abnormality diagnosis of out-of-plane vibration of driving leg>
Two output voltages output from the subtracting means 201 and 202 are input to the adding means 211 and added. The output of the adding means 211 is input to the synchronous detection circuit 212, and the synchronous detection circuit 212 synchronously detects the signal input from the adding means 211 by the signal output from the phase shift circuit 72, as in the above-described synchronous detection circuit 204. . Detection output of the synchronous detection circuit 212 is rectified and smoothed by the rectifier circuit 213 and a low pass filter 214, the output _{S 12.} The comparator 215 receives the constant voltage V _12H output from the constant voltage circuit 216 and the output S ₁₂ , while the comparator 217 receives the constant voltage V _12L output from the constant voltage circuit 218 and the output S _12. Is done.

The output S ₁₂ shoulder portion 11a, corresponding to the amplitude of the out-of-plane vibration of the same phase that occurs 11b during angular uninput, that is, represents the magnitude of the amplitude. Therefore, to set the constant voltage V _12H to the maximum value of the output S ₁₂ is judged to be normal operating state of the angular velocity has not been input, and sets a constant voltage V _12L to the minimum value of the output S ₁₂ is judged to be normal operating conditions .

Comparator 215 compares the output _{S 12} and a constant voltage _{V 12H,} when the V 12H _{<S 12,} and outputs "1" as a comparison result. The output K _{1 of the} comparator 215 is “0” when normal (when V _12H ≧ S ₁₂ ), and becomes “1” when the amplitude is abnormal. On the other hand, the comparator 217 compares the output _{S 12} and a constant voltage _{V 12L,} when V 12L _{<S 12,} and outputs "1" as a comparison result. Here, since it is necessary to reverse the diagnosis result, the output of the comparator 217 is passed to the NOT circuit 219. Output _{K 2} of the NOT circuit 219 at the normal time _{(when V 12L} ≦ _{S 12)} is "0", _(when V _{12L> S 12)} when the amplitude small abnormalities, a "1".

<Balancing abnormality diagnosis of out-of-plane vibration of detection leg>
The electrodes 17a-1 and 17a-2 provided on the shoulder 11c have the same polarity, and the subtraction means 221 calculates the detection voltage extracted from these electrodes 17a-1 and 17a-2 and the detection voltage extracted from the electrode 17b. To be subtracted (differential output). Similarly, the detection voltage extracted from the electrodes 18a-1 and 18a-2 provided on the shoulder 11d and the detection voltage extracted from the electrode 18b are input to the subtracting means 222 and subtracted.

The two output voltages output from the subtracting means 221 and 222 indicate out-of-plane vibrations of the shoulder portions 11c and 11d, respectively. The two output voltages are input to the subtracting means 223 and are subtracted. The output of the subtracting means 223 is input to the synchronous detection circuit 224. The synchronous detection circuit 224 performs synchronous detection on the signal input from the subtracting means 223 using the signal output from the phase shift circuit 72. Detection output of the synchronous detection circuit 224 is rectified and smoothed by the rectifier circuit 225 and a low pass filter 226, the output _{S 13.} A constant voltage V ₁₃ and an output S ₁₃ output from the constant voltage circuit 228 are input to the comparator 227.

The output S ₁₃ is zero ideally during angular missing. However, the shoulder portion 11c, when the unbalance plane vibration of the same phase of 11d occurs, becomes a certain value, thus the output S ₁₃ can become a normal operating state value constant (maximum acceptable) Voltage V ₁₃ Set. The comparator 227 compares the output S ₁₃ with the constant voltage V ₁₃ and outputs “1” as a comparison result when V ₁₃ <S ₁₃ . The output L of the comparator 227 is “0” when normal (when V ₁₃ ≧ S ₁₃ ), and becomes “1” when the balance is abnormal.

<Amplitude abnormality diagnosis of out-of-plane vibration of detection leg>
Two output voltages output from the subtracting means 221 and 222 are input to the adding means 231 and added. The output of the adding means 231 is input to the synchronous detection circuit 232, and the synchronous detection circuit 232 synchronously detects the signal input from the adding means 231 by the signal output from the phase shift circuit 72. Detection output of the synchronous detection circuit 232 is rectified and smoothed by the rectifier circuit 233 and a low pass filter 234, the output _{S 14.} The comparator 235 receives the constant voltage V ₁₄ output from the constant voltage circuit 236 and the output S ₁₄ .

The output S ₁₄ shoulder portion 11c, corresponding to the amplitude of the out-of-plane vibration of the same phase generated 11d during angular uninput, that is, it represents the magnitude of the amplitude. Therefore, to set the constant voltage V ₁₄ to the maximum value of the output S ₁₄ is judged to be normal operating state of the angular velocity has not been input,. Comparator 235 compares the output _{S 14} and a constant voltage _{V 14,} when the V _{14 <S} 14, and outputs "1" as a comparison result. The output M of the comparator 235 is “0” when normal (when V ₁₄ ≧ S ₁₄ ), and is “1” when the amplitude is abnormal.

The outputs J, K ₁ , L, and M of the comparators 207, 215, 227, and 235 described above and the output K ₂ of the NOT circuit 219 are input to the OR circuit 209, and the OR circuit 209 outputs the outputs J, K ₁ , and K _2. , L, and M, if there is “1”, “1” is output as a self-diagnosis output. Therefore, the abnormality can be detected by the self-diagnosis output “1”.

Thus, the driving legs ₁₂ 1, 12 ₂ side of the both shoulder portions 11a, plane vibration and the detection leg ₁₃ 1 11b, 13 ₂ side of the both shoulder portions 11c, the surface of the 11d of the body 11 according to this embodiment The external vibration can be detected by the piezoelectric effect, and by using these detection voltages, as described above, the abnormality diagnosis of the out-of-plane vibration (balance, amplitude) of the drive legs 12 ₁ and 12 ₂ and detection legs ₁₃ 1, 13 ₂ of the out-of-plane vibration (balance, amplitude) which is intended to perform the abnormality diagnosis.

[Example 3]
In this example, the out-of-plane vibration of the shoulder portions 11a to 11d of the body portion 11 is detected by a change in capacitance instead of the piezoelectric effect, and by using a detection voltage detected by the change in capacitance. It is assumed that abnormality diagnosis of out-of-plane vibration of the driving legs 12 ₁ and 12 ₂ and the detection legs 13 ₁ and 13 ₂ is performed. In this example, similarly to the first embodiment, the vibrator 10 may be either formed using a Z-cut piezoelectric single crystal or formed using an X-cut piezoelectric single crystal.

FIG. 11 shows an arrangement configuration of electrodes for detecting capacitance, both shoulders 11a and 11b on the driving legs 12 ₁ and 12 ₂ side and both detection legs 13 ₁ and 13 ₂ side of the body 11. Electrodes 25 ₁ , 25 ₂ , 26 ₁ , and 26 ₂ are formed on the surfaces of the shoulder portions 11c and 11d that face the base surface 22a, respectively. Electrodes 27 ₁ , 27 ₂ , 28 ₁ , and 28 ₂ are formed on the base surface 22a so as to face these electrodes 25 ₁ , 25 ₂ , 26 ₁ , and 26 ₂ , respectively. The electrode _{27 1,} 27 _2, 28 1, 28 ₂ FIG. 11 (c), the is a as shown (d), the electrode ₂₅ 1 facing _each 25 _2, 26 1, 26 ₂ from the wide Yes.

  Hereinafter, various abnormality diagnosis in this example will be described with reference to the self-diagnosis circuit shown in FIG. In addition, the electrostatic capacitance change of each counter electrode shall be detected as a voltage change from the electrode formed in the base surface 22a.

<Diagnosis of balance abnormality of out-of-plane vibration of driving leg>
The capacitance changes of the electrodes 27 ₁ and 27 ₂ that detect out-of-plane vibrations of the shoulder portions 11 a and 11 b are detected as voltage changes by the detection circuits 301 and 302, respectively. The detected voltage is input to the subtracting means 303 and subtracted. The output of the subtracting means 303 is input to the synchronous detection circuit 304. The synchronous detection circuit 304 synchronously detects the signal input from the subtracting means 303 by using a signal (phase shift circuit 72) that is phase-adjusted by delaying the phase of the drive signal output from the drive circuit 71 by 90 degrees. . Detection output of the synchronous detection circuit 304 is rectified and smoothed by the rectifier circuit 305 and a low pass filter 306, the output _{S 21.} A constant voltage V ₂₁ and an output S ₂₁ output from the constant voltage circuit 308 are input to the comparator 307.

The output S ₂₁ is zero ideally during angular missing. However, the shoulder portion 11a, the unbalance plane vibration of the same phase of 11b occurs, becomes a certain value, thus the output S ₂₁ can become a normal operating state value constant (maximum acceptable) Voltage V ₂₁ Set. The comparator 307 compares the output S ₂₁ with the constant voltage V _21, and outputs “1” as the comparison result when V ₂₁ <S ₂₁ . The output N of the comparator 307 is “0” when normal (when V ₂₁ ≧ S ₂₁ ), and becomes “1” when the balance is abnormal.

<Amplitude abnormality diagnosis of out-of-plane vibration of driving leg>
Two detection voltages output from the detection circuits 301 and 302 are input to the adding means 311 and added. The output of the adding means 311 is input to the synchronous detection circuit 312, and the synchronous detection circuit 312 performs synchronous detection of the signal input from the addition means 311 by the signal output from the phase shift circuit 72, as in the above-described synchronous detection circuit 304. . Detection output of the synchronous detection circuit 312 is rectified and smoothed by the rectifier circuit 313 and a low pass filter 314, the output _{S 22.} The comparator 315 receives the constant voltage V _22H output from the constant voltage circuit 316 and the output S ₂₂ , while the comparator 317 receives the constant voltage V _22L output from the constant voltage circuit 318 and the output S _22. Is done.

The output S ₂₂ shoulder portion 11a, corresponding to the amplitude of the out-of-plane vibration of the same phase that occurs 11b during angular uninput, that is, represents the magnitude of the amplitude. Accordingly, the constant voltage V _22H is set to the maximum value of the output S ₂₂ that is determined to be a normal operation state when the angular velocity is not input, and the constant voltage V _22L is set to the minimum value of the output S ₂₂ that is determined to be a normal operation state. .

Comparator 315 compares the output _{S 22} and a constant voltage _{V 22H,} when the V 22H _{<S 22,} and outputs "1" as a comparison result. The output P _{1 of the} comparator 315 is “0” when normal (when V _22H ≧ S ₂₂ ), and becomes “1” when the amplitude is abnormal. On the other hand, the comparator 317 compares the output _{S 22} and a constant voltage _{V 22L,} when V 22L _{<S 22,} and outputs "1" as a comparison result. Here, since it is necessary to reverse the diagnosis result, the output of the comparator 317 is passed to the NOT circuit 319. The output P ₂ of the NOT circuit 319 is “0” when normal (when V _22L ≦ S ₂₂ ), and is “1” when the amplitude is small and abnormal (when V _22L > S ₂₂ ).

<Diagnosis of balance abnormality of out-of-plane vibration of detection leg>
Shoulders portion 11c, the electrostatic capacitance change of the electrode ₂₈ 1, 28 ₂ which detects the plane vibration of 11d are detected respectively as voltage change by the detection circuit 321 and 322, two output from these detection circuits 321 and 322 The detection voltage is input to the subtraction means 323 and is subtracted. The output of the subtracting means 323 is input to the synchronous detection circuit 324. The synchronous detection circuit 324 performs synchronous detection on the signal input from the subtracting means 323 using the signal output from the phase shift circuit 72. Detection output of the synchronous detection circuit 323 is rectified and smoothed by the rectifier circuit 325 and a low pass filter 326, the output _{S 23.} The comparator 327 receives the constant voltage V ₂₃ output from the constant voltage circuit 328 and the output S ₂₃ .

The output S ₂₃ is zero ideally during angular missing. However, the shoulder portion 11c, when the unbalance plane vibration of the same phase of 11d occurs, becomes a certain value, thus the output S ₂₃ can become a normal operating state value constant (maximum acceptable) Voltage V ₂₃ Set. The comparator 327 compares the output S ₂₃ with the constant voltage V _23, and when V ₂₃ <S ₂₃ , outputs “1” as the comparison result. The output Q of the comparator 327 is “0” when normal (when V ₂₃ ≧ S ₂₃ ), and becomes “1” when the balance is abnormal.

<Amplitude abnormality diagnosis of out-of-plane vibration of detection leg>
Two detection voltages output from the detection circuits 321 and 322 are input to the adding means 331 and added. The output of the adding means 331 is input to the synchronous detection circuit 332, and the synchronous detection circuit 332 synchronously detects the signal input from the adding means 331 by the signal output from the phase shift circuit 72. Detection output of the synchronous detection circuit 332 is rectified and smoothed by the rectifier circuit 333 and a low pass filter 334, the output _{S 24.} A constant voltage V ₂₄ and an output S ₂₄ output from the constant voltage circuit 336 are input to the comparator 335.

The output S ₂₄ shoulder portion 11c, corresponding to the amplitude of the out-of-plane vibration of the same phase generated 11d during angular uninput, that is, it represents the magnitude of the amplitude. Accordingly, the constant voltage V ₂₄ is set to the maximum value of the output S ₂₄ that is determined as a normal operation state when the angular velocity is not input. The comparator 335 compares the output S ₂₄ with the constant voltage V ₂₄ and outputs “1” as the comparison result when V ₂₄ <S ₂₄ . The output R of the comparator 335 is “0” when normal (when V ₂₄ ≧ S ₂₄ ), and becomes “1” when the amplitude is abnormal.

The outputs N, P ₁ , Q, R of the comparators 307, 315, 327, and 335 described above and the output P ₂ of the NOT circuit 319 are input to the OR circuit 309, and the OR circuit 309 outputs the outputs N, P ₁ , P _2. , Q, and R, if there is at least “1”, “1” is output as the self-diagnosis output. Therefore, the abnormality can be detected by the self-diagnosis output “1”.

Thus, the driving legs ₁₂ 1, 12 ₂ side of the both shoulder portions 11a, plane vibration and the detection leg ₁₃ 1 11b, 13 ₂ side of the both shoulder portions 11c, the surface of the 11d of the body 11 according to this embodiment The external vibration can be detected by a change in electrostatic capacitance, and by using these detection voltages, the out-of-plane vibrations (balance, balance) of the drive legs 12 ₁ and 12 ₂ are used as in the second embodiment. abnormality diagnosis and detection legs 13 _1, 13 ₂ of the out-of-plane vibration (balance amplitude), which is intended to perform the abnormality diagnosis amplitude).

(A) is a perspective view for demonstrating the structure of the vibrator | oscillator in the 1st Example of the tuning fork type vibration gyroscope by this invention, (b) is the side view which abbreviate | omitted the part. (A) is a partially omitted plan view showing an electrode arrangement with respect to the vibrator of FIG. 1, (b) is an HH sectional view of (a), and (c) is an II sectional view of (a). The figure for demonstrating the electrode which detects the vibration of a driving leg by an electrostatic capacitance change. The figure for demonstrating the electrode which detects the vibration of a detection leg by an electrostatic capacitance change. FIG. 5 is a block diagram illustrating a configuration example of a self-diagnosis circuit included in a tuning-fork type vibration gyro having the electrode arrangement illustrated in FIGS. FIG. 5 is a block diagram illustrating a configuration example of a self-diagnosis circuit included in a tuning-fork type vibration gyro having the electrode arrangement illustrated in FIGS. The figure for demonstrating the out-of-plane vibration of the both shoulders of a drive leg and a trunk | drum, (a) shows normal time, (b) shows the time of abnormality (at the time of failure occurrence). The figure for demonstrating the electrode arrangement | positioning for abnormality detection in the 2nd Example of the tuning fork type vibration gyro by this invention. FIG. 9 is a block diagram showing a configuration example of a self-diagnosis circuit included in a tuning fork type vibration gyro having the electrode arrangement shown in FIG. 8. The figure for demonstrating an example of the detection voltage taken out by the out-of-plane vibration of the both shoulder parts of the trunk | drum at the time of abnormality generation, and the electrode provided in both shoulder parts. The figure for demonstrating the electrode arrangement | positioning for abnormality detection in the 3rd Example of the tuning fork type vibration gyro by this invention. FIG. 12 is a block diagram showing a configuration example of a self-diagnosis circuit included in a tuning fork type vibration gyro having the electrode arrangement shown in FIG. 11.

Claims (14)

A vibrator formed of a plate-like piezoelectric body is mounted on a base via a support portion with its plate surface parallel to the base surface, and the vibrator includes a body portion supported by the support portion, A pair of drive legs and a pair of detection legs projecting in opposite directions from opposite side surfaces of the body portion are provided, and the drive legs are caused to vibrate in-plane in a direction parallel to the base surface. A tuning fork type vibration gyro, in which drive electrodes for each are formed, and detection electrodes for detecting out-of-plane vibrations in the direction perpendicular to the base surface of the detection legs are respectively formed on the pair of detection legs,
Electrodes for detecting the in-plane vibrations of the drive legs and the out-of-plane vibrations in the direction perpendicular to the base surface are detected on the opposing surfaces of the pair of drive legs and the base, respectively, by changes in capacitance. And
An electrode for detecting the out-of-plane vibration of the detection legs by a change in capacitance is formed on the opposing surfaces of the pair of detection legs and the base,
A tuning-fork type vibration gyro comprising a self-diagnosis circuit that performs abnormality diagnosis using each detection voltage detected by capacitance change of the electrodes. The tuning fork type vibrating gyroscope according to claim 1,
The self-diagnosis circuit includes a circuit for diagnosing abnormal vibration in the plane of the pair of drive legs, a circuit for diagnosing abnormal vibration in the plane of the pair of drive legs, and out-of-plane vibration of the pair of detection legs. A tuning fork type vibration gyro comprising a circuit for diagnosing abnormality of a gyro output. In the tuning fork type vibration gyro according to claim 2,
The circuit for diagnosing abnormal vibration in the plane of the pair of drive legs is as follows:
An adding means for adding two detection voltages each of which detects in-plane vibrations of the pair of drive legs by a capacitance change;
Means for comparing the output of the adding means with the rectified and smoothed output and a constant voltage V ₁ and outputting a comparison result;
Subtracting means for subtracting the two detection voltages;
And an output thereof is rectified and smoothed output of the subtraction means, the tuning fork type vibrating gyro, characterized in that it comprises a means for outputting to a comparison result compared with the predetermined voltage V _2. In the tuning fork type vibration gyro according to claim 2,
The circuit for diagnosing the abnormality of out-of-plane vibration of the pair of drive legs is
Adding means for adding two detection voltages, each of which detects the out-of-plane vibration of the pair of drive legs by a capacitance change;
A drive signal input to output to the drive electrodes of the addition means synchronously detects the phase adjustment signal, an output obtained by rectifying and smoothing the detected output, a to the comparison result compared with the predetermined voltage V ₃ output Means to
Subtracting means for subtracting the two detection voltages;
The output of the subtraction means synchronously detects the signal the phase adjustment, and characterized in that it comprises an output which is rectified and smoothed its detection output, and means for outputting to a comparison result compared with the predetermined voltage V ₄ A tuning fork-type vibrating gyroscope. In the tuning fork type vibration gyro according to claim 2,
The circuit for diagnosing out-of-plane vibration of the pair of detection legs and abnormality of the gyro output is as follows:
First subtracting means for subtracting two detection voltages, each of which detects out-of-plane vibrations of the pair of drive legs by a capacitance change;
Means for synchronously detecting the output of the first subtracting means with a signal obtained by adjusting the phase of the drive signal inputted to the drive electrode, rectifying and smoothing the detected output, and further adjusting the gain to obtain the first output; ,
A second subtracting means for subtracting two detection voltages obtained by detecting the out-of-plane vibration of the pair of detection legs by a capacitance change;
Means for synchronously detecting the output of the second subtracting means with the phase-adjusted signal, rectifying and smoothing the detected output, and further adjusting the gain to obtain a second output;
Means for synchronously detecting the output of the second subtracting means with the drive signal, rectifying and smoothing the detected output, and further adjusting the gain to obtain a third output;
A detection signal obtained by subtracting two detection voltages respectively extracted from the detection electrodes of the pair of detection legs is synchronously detected by the phase-adjusted signal, and a fourth output obtained by rectifying and smoothing the detection output; Means for comparing the first output and outputting a comparison result;
Means for comparing the second output with the fourth output and outputting a comparison result;
The gyro output obtained by synchronously detecting the detection signal with the drive signal and rectifying and smoothing the detection output is compared with the third output to output a comparison result. Tuning fork type vibration gyro. The tuning fork type vibrating gyroscope according to claim 1,
The tuning fork type vibration gyro characterized in that the electrode for detecting in-plane vibration of the drive leg has a comb shape. A vibrator formed of a plate-like piezoelectric body is mounted on a base via a support portion with its plate surface parallel to the base surface, and the vibrator includes a body portion supported by the support portion, A pair of drive legs and a pair of detection legs projecting in opposite directions from opposite side surfaces of the body portion are provided, and the drive legs are caused to vibrate in-plane in a direction parallel to the base surface. A tuning fork type vibration gyro, in which drive electrodes for each are formed, and detection electrodes for detecting out-of-plane vibrations in the direction perpendicular to the base surface of the detection legs are respectively formed on the pair of detection legs,
Electrodes for detecting out-of-plane vibrations perpendicular to the base surface of the shoulders by the piezoelectric effect are formed on both shoulders on the driving leg side and both shoulders on the detection leg side in the body part,
A tuning-fork type vibration gyro comprising a self-diagnosis circuit that performs abnormality diagnosis using each detection voltage detected by these electrodes. The tuning-fork type vibration gyro according to claim 7,
The self-diagnosis circuit includes a circuit for diagnosing an abnormality in out-of-plane vibration of the pair of drive legs, and a circuit for diagnosing an abnormality in out-of-plane vibration of the pair of detection legs. . The tuning-fork type vibration gyro according to claim 8,
The circuit for diagnosing the abnormality of out-of-plane vibration of the pair of drive legs is as follows:
Subtracting means for subtracting two detection voltages respectively detecting out-of-plane vibrations of both shoulders on the drive leg side;
A drive signal input to output to the drive electrode of the subtraction means synchronously detects the phase adjustment signal, an output obtained by rectifying and smoothing the detected output, a to the comparison result compared with the constant voltage V ₁₁ output Means to
Adding means for adding the two detection voltages;
The output of the adding means is synchronously detected by the phase-adjusted signal, the output obtained by rectifying and smoothing the detected output, and means for comparing the constant voltages V _12H and V _12L with each other and outputting a comparison result are provided. A tuning-fork type vibration gyro characterized by that. The tuning-fork type vibration gyro according to claim 8,
The circuit for diagnosing the abnormality of out-of-plane vibration of the pair of detection legs is as follows:
Subtracting means for subtracting two detection voltages respectively detecting out-of-plane vibrations of both shoulders on the detection leg side;
A drive signal input to output to the drive electrode of the subtraction means synchronously detects the phase adjustment signal, an output obtained by rectifying and smoothing the detected output, a to the comparison result compared with the constant voltage V ₁₃ output Means to
Adding means for adding the two detection voltages;
The output of the addition means synchronously detects the signal the phase adjustment, and characterized in that it comprises an output which is rectified and smoothed its detection output, and means for outputting to a comparison result compared with the constant voltage V ₁₄ A tuning fork-type vibrating gyroscope. A vibrator formed of a plate-like piezoelectric body is mounted on a base via a support portion with its plate surface parallel to the base surface, and the vibrator includes a body portion supported by the support portion, A pair of drive legs and a pair of detection legs projecting in opposite directions from opposite side surfaces of the body portion are provided, and the drive legs are caused to vibrate in-plane in a direction parallel to the base surface. A tuning fork type vibration gyro, in which drive electrodes for each are formed, and detection electrodes for detecting out-of-plane vibrations in the direction perpendicular to the base surface of the detection legs are respectively formed on the pair of detection legs,
Capacitance of out-of-plane vibrations in the direction perpendicular to the base surface of the shoulders on the opposite surfaces of the shoulders on the driving leg side and the shoulders on the detection leg side and the base in the body part Each of the electrodes for detection by the change of
A tuning-fork type vibration gyro comprising a self-diagnosis circuit that performs abnormality diagnosis using each detection voltage detected by capacitance change of the electrodes. The tuning fork type vibrating gyroscope according to claim 11,
The self-diagnosis circuit includes a circuit for diagnosing an abnormality in out-of-plane vibration of the pair of drive legs, and a circuit for diagnosing an abnormality in out-of-plane vibration of the pair of detection legs. . The tuning fork type vibrating gyroscope according to claim 12,
The circuit for diagnosing the abnormality of out-of-plane vibration of the pair of drive legs is as follows:
Subtracting means for subtracting two detection voltages, each of which detects out-of-plane vibrations of both shoulders on the drive leg side by capacitance change;
A drive signal input to output to the drive electrode of the subtraction means synchronously detects the phase adjustment signal, an output obtained by rectifying and smoothing the detected output, a to the comparison result compared with the constant voltage V ₂₁ output Means to
Adding means for adding the two detection voltages;
The output of the adding means is synchronously detected by the phase-adjusted signal, the output obtained by rectifying and smoothing the detected output, and means for comparing the constant voltages V _22H and V _22L with each other and outputting a comparison result are provided. A tuning-fork type vibration gyro characterized by that. The tuning fork type vibrating gyroscope according to claim 12,
The circuit for diagnosing the abnormality of out-of-plane vibration of the pair of detection legs is
Subtracting means for subtracting two detection voltages, each of which detects out-of-plane vibration of both shoulders on the detection leg side by a capacitance change,
A drive signal input to output to the drive electrode of the subtraction means synchronously detects the phase adjustment signal, an output obtained by rectifying and smoothing the detected output, a to the comparison result compared with the constant voltage V ₂₃ output Means to
Adding means for adding the two detection voltages;
The output of the adding means is synchronously detected by the phase-adjusted signal, and the output obtained by rectifying and smoothing the detected output is compared with the constant voltage V ₂₄ and the comparison result is output. A tuning fork-type vibrating gyroscope.

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