JP2010096552A - Method and device of calibrating vibration velocity sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To calibrate a scale factor of a vibration velocity sensor by generating vibration motion having large amplitude and using the vibration motion. <P>SOLUTION: The vibration velocity sensor S to be calibrated is placed on a rotary table 14 coupled to a rotary drive source built in a rotary unit 12 so that an input shaft of the vibration velocity sensor S matches with the rotation direction of the rotary table 14. The rotary table 14 is rotated and vibrated at a certain rotation frequency so that the vibrating vibration velocity is input to the vibration velocity sensor S. The output signal from the vibration velocity sensor S is obtained, and the scale factor of the vibration velocity sensor S is calculated from the obtained output signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and apparatus for calibrating a vibration speed sensor that measures vibration speeds such as earthquakes and shaking of buildings.

  As a conventional vibration speed sensor, the one described in Patent Document 1 is known. The servo-type vibrometer described in Patent Document 1 includes a pendulum, and vibration displacement acting on the pendulum is converted into an electric signal by a displacement detector, and this displacement output is supplied to a drive unit via an amplifier. It has come to be. The vibration acting on the pendulum is detected by the displacement detector as an electrical signal of the pendulum. This is output via the amplifier. At the same time, the electrical signal from the amplifier is fed back to the drive unit via the differentiation circuit. In the drive unit, a restoring force corresponding to the magnitude of the differential output of the displacement of the pendulum acts, and a force that returns the pendulum to its original position is generated.

  By setting the gain of the amplifier large, the amount of displacement of the pendulum is proportional to the speed of displacement with respect to the space of the vibrometer, so that the output from the amplifier can be obtained as a speed signal.

  In Japanese Patent Application No. 2008-67097 filed by the present applicant, a discrimination means for discriminating an output signal from a pickup for detecting the displacement of a pendulum into a high frequency signal and a low frequency signal according to frequency, and a high frequency from the discrimination means. A first amplifying means for amplifying the area signal to obtain a feedback signal; an integrating means for integrating the high-frequency signal from the discriminating means to obtain a vibration speed signal; and a feedback by differentiating the low-frequency signal from the discriminating means. Servo-type vibration speed having a differential means for making a signal and a second amplification means for amplifying a low-frequency signal from the discrimination means to make a vibration speed signal, and obtaining a highly sensitive vibration speed signal in a wide band Sensors have been proposed.

  By the way, when such a vibration speed sensor is put into practical use, it is necessary to calibrate the scale factor. Therefore, it is conceivable to use a vibration device that generates a vibration motion as shown in FIG. 14 for calibration.

  14 includes a vibration unit 42, a vibration table 44 coupled to the vibration unit 42, a base 46 that guides the vibration table 44, and a controller 48 that controls the amplitude and frequency of the vibration unit 42. The vibration table 44 can linearly vibrate on the base 46 in the horizontal direction, and the vibration speed sensor S to be calibrated is installed on the vibration table 44 with the input shaft aligned with the vibration direction. Since the vibration speed signal having the amplitude and frequency given from the controller 48 is detected and output, it is conceivable to calibrate the scale factor from this output signal.

Japanese Utility Model Publication No. 6-28698

  However, this type of vibration device has a problem that the stroke of the vibration unit 42 is limited, and it is difficult to generate vibration with a low frequency and a large amplitude.

  For example, if the vibration speed is A = 1 [m / sec] and the vibration frequency is f = 0.1 [Hz], the vibration displacement a [m], which is the vibration amplitude, is

とかなり大きくなる。更にf=0.01 [Hz]ともなればa=16 [m]となって、このような長いストロークを直線的に振動台４４にさせるのは現実的ではない、という問題がある。

And it gets quite big. Furthermore, when f = 0.01 [Hz], a = 16 [m] is obtained, and there is a problem that it is not practical to linearly make such a long stroke to the shaking table 44.

  The present invention has been made in view of such a problem, and an object of the present invention is to calibrate a vibration speed sensor capable of generating a vibration having a large amplitude and calibrating the scale factor of the vibration speed sensor using the vibration. It is to provide a method and apparatus.

To achieve the above object, the present invention provides a vibration speed sensor calibration method for calibrating a scale factor of a vibration speed sensor.
The vibration speed sensor is installed on a turntable coupled to a rotation drive source so that the input shaft thereof matches the rotation direction of the turntable,
The rotating table is rotated so as to vibrate at a certain rotation frequency, and a vibration speed that vibrates is input to the vibration speed sensor.
Obtain the output signal from the vibration speed sensor,
Calculating a scale factor from the acquired output signal;
It is characterized by that.

According to a second aspect of the present invention, an acceleration sensor is installed on the turntable according to the first aspect of the invention so that its input shaft matches the rotation direction of the turntable,
Obtaining an output signal from the acceleration sensor together with an output signal from the vibration speed sensor;
The calculation of the scale factor uses an output signal from the acquired acceleration sensor.
It is characterized by that.

According to a third aspect of the present invention, an acceleration sensor is installed on the turntable according to the first aspect so that an input shaft thereof is aligned with a radial direction orthogonal to the rotation direction of the turntable,
Obtaining an output signal from the acceleration sensor together with an output signal from the vibration speed sensor;
The calculation of the scale factor uses an output signal from the acquired acceleration sensor.
It is characterized by that.

  According to a fourth aspect of the present invention, a scale factor calibrated in advance of the acceleration sensor is used for the calculation of the scale factor according to the second or third aspect.

  A fifth aspect of the present invention is characterized in that the acceleration sensor and the vibration speed sensor according to any one of the second to fourth aspects are arranged on the same circumference of a turntable.

According to a sixth aspect of the present invention, in the method according to the first aspect, the calibrated reference vibration speed sensor is installed on the turntable so that an input shaft thereof matches a rotation direction of the turntable.
Obtaining an output signal from the reference vibration speed sensor together with an output signal from the vibration speed sensor;
The calculation of the scale factor uses an output signal from the acquired reference vibration speed sensor and a pre-calibrated scale factor of the reference vibration speed sensor.
It is characterized by that.

  According to a seventh aspect of the present invention, the reference vibration speed sensor according to the sixth aspect and the vibration speed sensor are arranged on the same circumference of a turntable.

The present invention according to claim 8 is a vibration speed sensor calibration apparatus used in the vibration speed sensor calibration method according to any one of claims 1 to 7,
A rotation drive source; a turntable coupled to the rotation drive source; a base that rotatably supports the turntable; and a controller that controls a rotation frequency of the turntable.

  According to the present invention, by rotating the turntable so as to vibrate at a certain rotation frequency, it is possible to generate a vibration motion having a large amplitude without increasing the size of the turntable. Therefore, it is possible to realize a motion with a large vibration speed, and to calculate the scale factor of the vibration speed sensor with high accuracy.

  By installing an already calibrated acceleration sensor or reference vibration speed sensor on the turntable, simultaneously obtaining output signals and using these output signals, the parameters required for calculating the scale factor can be reduced. it can.

  By arranging the acceleration sensor or the reference vibration speed sensor on the same circumference of the turntable, it is possible to further reduce the parameters necessary for calculating the scale factor.

  Hereinafter, the present invention will be described with reference to the drawings.

(First embodiment)
1 to 3 are views showing a first embodiment of a vibration speed sensor calibration apparatus for performing the vibration speed sensor calibration method of the present invention.

  The vibration speed sensor calibration apparatus 10 includes a rotary unit 12 having a built-in rotary drive source, a rotary base 14 coupled to the rotary drive source of the rotary unit 12, a base 16 that supports the rotary base 14, and the rotary base 14. The controller 18 controls the rotation frequency of the motor, the rotation sensor 20, the recording device 22, and the analysis device 24. The turntable 14 is preferably rotatably supported on the base 16 by an air bearing.

  The vibration speed sensor S to be calibrated is installed on the turntable 14 with the input shaft aligned with the rotation direction of the turntable 14, and the signal output from the vibration speed sensor S is recorded as an analog or digital signal in the recording device 22. The The signal recorded by the recording device 22 is analyzed by the analyzing device 24. The recording device 22 and the analysis device 24 can be configured as the same device, for example, a computer. The recording device 22 is connected to the vibration speed sensor S by an appropriate connecting means via a slip ring or the like, and can be installed at a location away from the turntable 14 or installed on the turntable 14. It is also possible.

  The controller 18 operates the turntable 14 at a controlled rotation frequency, includes a driver circuit for the rotation unit 12, and supplies a drive signal to the rotation unit 12.

Here, the controller 18 rotates the turntable 14 so as to vibrate at the rotation frequency f ₀ [Hz]. As a result, when the rotating table 14 is set to ω ₀ = 2πf ₀ , the rotation angular velocity ω [rad / sec] is set to t as time.

となるように振動する。ここで、a₀[rad]は振幅である。

It vibrates to become. Here, a ₀ [rad] is the amplitude.

  The above control of the controller 18 may output a drive signal based on a value sequentially calculated by the controller 18 based on the equation (2), or a value calculated by the equation (2) by a computer other than the controller 18 may be used as the controller. 18 may be given as an instruction signal from the outside. Alternatively, a drive signal may be output from the controller 18 by a method in which a sine wave signal is given from the outside and caused to follow this signal.

  The rotation sensor 20 is for detecting the rotation angle of the turntable 14, and can be constituted by an encoder that outputs a pulse signal for each predetermined rotation angle of the turntable 14, for example. A signal from the rotation sensor 20 is converted into an angle by the recording device 22 and recorded.

According to the rotation frequency f ₀ supplied from the controller 18, the turntable 14 is rotated and vibration in the rotational angular velocity omega, the vibration velocity sensor S detects and outputs the vibration velocity of the turntable 14 as the voltage E _v. The output voltage _Ev is recorded by the recording device 22, and the scale factor is calibrated by the following analysis processing or the like.

FIG. 2 shows an installation example of the vibration speed sensor S on the turntable 14. When a rotational angular velocity such as the equation (2) is given, the rotational speed v _{φ at} the point of the rotational radius r [m] in FIG.

となる。この点に振動速度センサＳを置けば、（３）式で与えられる振動速度が振動速度センサＳに入力される。

It becomes. If the vibration speed sensor S is placed at this point, the vibration speed given by the equation (3) is input to the vibration speed sensor S.

FIG. 3 shows the scale factor of the vibration speed sensor S to be calibrated. When the input speed is v _i [m / sec] and the output voltage is E _v [V], the scale factor S _v [V / m / sec] of the vibration speed sensor S is

である。（３）式のv_φと（４）式のv_iが等しければ

It is. If v _{φ in} (3) is equal to v _{i in} (4)

であるので、振動成分に注目し、E_vの振幅値（ピーク値または実効値等）を｜E_v｜として、この値を測定するものとすれば

Since it is, paying attention to the vibration component, the amplitude value of E _v (peak value or effective value, etc.) | E _v | a, if used to measure this value

より、速度信号のスケールファクタS_vが求められる。

Thus, the scale factor S _v of the speed signal is obtained.

Further, the recording device 22 converts the angle by counting the pulse signal from the rotation sensor 20, and obtains and records the angle when the peak value of _Ev is reached.

Treatment with analyzer 24, or by the operator to handle using an analysis device 24, the voltage of the vibration velocity sensor S, the amplitude value of E _v (peak value or effective value, etc.) | E _v | a controller 18 using ω ₀ or f ₀ , the amplitude a ₀ [rad] obtained from the angle difference between the peak values of E _v , and the known turning radius r of the installation point of the vibration velocity sensor S, it can be obtained from (6) scale factor S _v. The amplitude a ₀ can also be obtained by any other means.

Further, by changing the omega ₀ in the controller 18, it is possible to obtain the frequency characteristics of the scale factor S _v.

  In the turntable 14 having a feasible size, vibration with a large amplitude can be generated by vibrating the turntable 14 so as to rotate over a plurality of turns. Therefore, a motion with a high vibration speed can be realized, and the vibration speed sensor S can be calibrated in a wide vibration speed range.

(Second Embodiment)
4-6 is a figure which shows 2nd Embodiment of the vibration speed sensor calibration apparatus which implements the vibration speed sensor calibration method of this invention. Means similar to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the vibration speed sensor calibration device 10 of this embodiment, an acceleration sensor 28 is installed in addition to the vibration speed sensor S to be calibrated on the turntable 14, and the input shaft of the vibration speed sensor S on the turntable 14 is Installed in the rotational direction, the input shaft of the acceleration sensor 28 is installed in the rotational direction in the same manner as the vibration speed sensor S to be calibrated.

  The vibration speed sensor S to be calibrated detects the vibration speed of the turntable 14 controlled by the controller 18 and outputs an output signal, while the acceleration sensor 28 is controlled by the controller 18. In response to the vibration of the turntable 14, the vibration acceleration of the vibration is detected and an output signal is output.

  Hereinafter, the operation of the vibration speed sensor calibration apparatus 10 according to the second embodiment will be described.

FIG. 5 shows an installation example of the speed sensor S and the acceleration sensor 28 on the turntable 14. When a rotational angular velocity as shown in equation (2) is given, the acceleration α _{φ in} the rotational direction at the point of the rotational radius r ₁ [m] in FIG.

である。この点に入力軸を回転方向とした加速度センサ２８を置けば、（７）式で与えられる振動加速度が加速度センサ２８に入力される。

It is. If the acceleration sensor 28 with the input shaft in the rotational direction is placed at this point, the vibration acceleration given by the equation (7) is input to the acceleration sensor 28.

FIG. 6 shows the scale factor of the acceleration sensor 28. When the input acceleration is α _i [m / sec ² ] and the output voltage is E _α [V], the scale factor S _α [V / m / sec ² ] of the acceleration sensor 28 is

である。（７）式のα_φと（８）式のα_iが等しければ

It is. If α _{φ in} equation (7) is equal to α _{i in} equation (8)

であるので、振動成分に注目し、E_αの振幅値（ピーク値または実効値等）を｜E_α｜を測定するものとすれば

Since it is, paying attention to the vibration component, the amplitude value of E _alpha (peak value or effective value, etc.) | Assuming that measures | E _alpha

である。（６）式に（１０）式の関係を代入すると

It is. Substituting the relationship of equation (10) into equation (6)

となる。ただし、

It becomes. However,

である。

It is.

This equation (11) does not include the amplitude a ₀ of the rotation angle of the turntable. Amplitude value of a measure E _v of (peak value or effective value, etc.) | E _v |, the amplitude value of E _alpha (peak value or effective value, etc.) | E _alpha | other, the acceleration sensor 28 The scale factor S _v of the vibration speed sensor S can be determined using the scale factor S _α , the value of the vibration frequency f ₀ (ω ₀ = 2πf ₀ ), and the rotation radii r and r ₁ of the turntable.

Thus, the second embodiment can provide the same operations and effects as the first embodiment. Furthermore, in the first embodiment, when the scale factor is obtained by the equation (6) and calibrated, it is necessary to measure the vibration amplitude a ₀ of the turntable 14 as a necessary parameter. In the second embodiment, The measurement of the amplitude a ₀ can be made unnecessary. As a result, the only necessary measurement values are the voltage values respectively output from the vibration speed sensor S and the acceleration sensor 28. Since these voltage values are electrical signals and can generally be measured with high accuracy, the scale factor of the vibration speed sensor S can be measured. S _v can be determined with high accuracy.

(Third embodiment)
7-9 is a figure which shows 3rd Embodiment of the vibration speed sensor calibration apparatus which implements the vibration speed sensor calibration method of this invention. The same means as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the vibration speed sensor calibration apparatus 10 of this embodiment, an acceleration sensor 30 is installed in addition to the vibration speed sensor S to be calibrated on the turntable 14, and the input shaft of the vibration speed sensor S on the turntable 14 is Installed in the rotational direction, the input shaft of the acceleration sensor 30 is installed in the radial direction orthogonal to the same rotational direction as the input shaft of the vibration speed sensor to be calibrated.

  The vibration speed sensor S detects the vibration speed of the turntable 14 controlled by the controller 18 and outputs an output signal, while the acceleration sensor 30 rotates the rotation controlled by the controller 18. For the vibration of the table 14, the vibration acceleration of the vibration is detected and an output signal is output.

  Hereinafter, the operation of the vibration speed sensor calibration apparatus 10 according to the third embodiment will be described.

FIG. 8 shows an installation example of the vibration speed sensor S and the acceleration sensor 30 on the turntable 14. When a rotational angular velocity as shown in equation (2) is given, the radial acceleration α _{r at} the point of the rotational radius r ₁ [m] in FIG.

である。この点に入力軸を回転方向に直交する半径方向とした加速度センサ３０を置けば、（１３）式で与えられる振動加速度が加速度センサ３０に入力される。

It is. If the acceleration sensor 30 with the input shaft in the radial direction orthogonal to the rotation direction is placed at this point, the vibration acceleration given by the equation (13) is input to the acceleration sensor 30.

FIG. 9 shows the scale factor of the acceleration sensor 30. When the input acceleration is β _i [m / sec ² ] and the output voltage is E _β [V], the scale factor S _β [V / m / sec ² ] of the acceleration sensor 30 is

である。尚、加速度センサ３０として、加速度センサ２８を用いれば、スケールファクタは、図６で示す通りとなる。

It is. If the acceleration sensor 28 is used as the acceleration sensor 30, the scale factor is as shown in FIG.

If α _{r in} equation (13) is equal to β _{i in} equation (14)

であるので、振動成分に注目し、E_βの振幅値（ピーク値または実効値等）を｜E_β｜を測定するものとすれば

Since it is, paying attention to the vibration component, the amplitude value of the E _beta (peak value or effective value, etc.) | Assuming that measures | E _beta

である。（６）式に（１６）式の関係を代入すると

It is. Substituting the relationship of equation (16) into equation (6)

となる。

It becomes.

This equation (17) does not include the amplitude a ₀ of the rotation angle of the turntable and the vibration frequency f ₀ (ω ₀ = 2πf ₀ ). Amplitude value of a measure E _v of (peak value or effective value, etc.) | E _v |, the amplitude value of the E _beta (peak value or effective value, etc.) | E _beta | other, the acceleration sensor 30 The scale factor S _v of the vibration speed sensor S can be determined using the scale factor S _β and the values of the rotation radii r and r ₁ of the turntable.

As a result, even in the third embodiment, the same effect as the second embodiment can be obtained, it is possible to reduce the necessary parameters for determining the scale factor S _v. The measurement of the output of the acceleration sensor 30 with respect to the low frequency vibration is easy because the output of the acceleration sensor 30 can obtain a signal having a double frequency.

In 2nd Embodiment and 3rd Embodiment, the acceleration sensors 28 and 30 are made into the reference | standard by calculating | requiring the scale factor of the acceleration sensors 28 and 30 previously. If the value of the vibration frequency f ₀ (ω ₀ = 2πf ₀ ) is given from the controller 18, then only the voltage value is measured, and the vibration speed sensor S at the given vibration frequency f ₀ (ω ₀ = 2πf ₀ ) is applied. Since the scale factor can be determined, calibration is easy.

  Note that the scale factors of the acceleration sensors 28 and 30 can be easily obtained by a known method, unlike the vibration speed sensor S, and use gravitational acceleration, give arbitrary centrifugal acceleration to the acceleration sensor, or Calibration can be performed by a method such as giving an electric signal in a pseudo manner. Unlike the vibration speed sensor S, the acceleration sensors 28 and 30 detect a direct current component, and since the frequency characteristics of the scale factor are small in a low frequency band, an accurate scale factor can be easily obtained.

FIG. 10 shows the output voltage E _v of the vibration speed sensor S whose input shaft is in the rotation direction, and the output voltage of the acceleration sensor 28 in which the input shaft according to the second embodiment of the present invention is installed in the same rotation direction as the vibration speed sensor S. An example of E _α and the output voltage E _β of the acceleration sensor 30 in which the input shaft according to the method of the third embodiment of the present invention is installed in the radial direction orthogonal to the same rotational direction as the vibration speed sensor S is shown. In FIG. 10, the frequency is 0.1 [Hz]. If the scale factor of the reference acceleration sensors 28 and 30 is known in advance by measuring the amplitude value (peak value or effective value) of the output voltage, the equation (11) or (17) is used. The scale factor of the vibration speed sensor S to be calibrated can be obtained.

(An example of the second embodiment and the third embodiment)
11 and 12 show an installation example in which the acceleration sensor 28 or 30 is installed on the same circumference as the vibration speed sensor S to be calibrated as an example of the second embodiment and the third embodiment.

  The vibration speed sensor S to be calibrated and the acceleration sensor 28 or 30 are attached to the turntable 14 together by a jig 32. By using the jig 32, the vibration speed sensor S and the acceleration sensor 28 or 30 do not need to be individually adjusted to have the same radius, and the installation becomes easy.

  Thus, by installing on the same circumference, equation (12) becomes

となり、（１１）式、または（１７）式がより簡単となる。（１１）式は

Thus, the formula (11) or the formula (17) becomes simpler. Equation (11) is

となってスケールファクタの校正に半径rの値が不要となる。（１７）式は

Thus, the value of radius r is not necessary for calibration of the scale factor. Equation (17) is

となって、予め振動速度センサＳと加速度センサ２８または３０の設置点の回転半径ｒの値を測定しておけばｒの値は固定値となるので、測定は電圧値だけとなる。この結果、振動速度センサＳのスケールファクタを精度よく測定できる。

Thus, if the value of the rotation radius r of the installation point of the vibration velocity sensor S and the acceleration sensor 28 or 30 is measured in advance, the value of r becomes a fixed value, so that the measurement is only a voltage value. As a result, the scale factor of the vibration speed sensor S can be accurately measured.

(Fourth embodiment)
FIG. 13 is a diagram showing a fourth embodiment of the vibration velocity sensor calibration apparatus for performing the vibration velocity sensor calibration method of the present invention. The same means as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

In the vibration velocity sensor calibration apparatus 10 of this embodiment, in addition to the vibration velocity sensor S to be calibrated on the turntable 14, the reference vibration velocity sensor 34 already a calibrated reference is placed on the rotary radius r ₁ The input shaft of the vibration speed sensor S on the turntable 14 is installed in the rotation direction, and the input shaft of the reference vibration speed sensor 34 is installed on the same input shaft as the vibration speed sensor to be calibrated. The reference vibration speed sensor 34 can be calibrated in advance by, for example, any one of the first to third embodiments.

If the scale factor of the reference vibration speed sensor 34 is S _Rv and the amplitude value (peak value or effective value, etc.) of the output voltage E _Rv of the reference vibration speed sensor 34 is | E _Rv |

となる。

It becomes.

According to the equation (21), | E _v | of the amplitude value (peak value or effective value, etc.) of E _v which is a measured value, | E _Rv | other than the amplitude value (peak value or effective value, etc.) of E _RV In addition, the scale factor S _v of the vibration speed sensor S can be determined using the scale factor S _Rv of the reference vibration speed sensor 34 and the rotation radii r and r ₁ of the turntable.

By installing the vibration speed sensor S to be calibrated and the reference vibration speed sensor 34 on the same circumference, R = 1, that is, r = r ₁ , and the scale factor S _v can be calculated more easily.

1 is a perspective view showing a first embodiment of a vibration speed sensor calibration apparatus for performing a vibration speed sensor calibration method of the present invention. It is a top view showing installation of the vibration speed sensor by a 1st embodiment. It is a block diagram showing the scale factor of a vibration speed sensor. It is a perspective view which shows 2nd Embodiment of the vibration speed sensor calibration apparatus which enforces the vibration speed sensor calibration method of this invention. It is a top view showing installation of a vibration speed sensor and an acceleration sensor by a 2nd embodiment. It is a block diagram showing the scale factor of the acceleration sensor in which the input shaft was installed in the rotation direction. It is a perspective view which shows 3rd Embodiment of the vibration speed sensor calibration apparatus which enforces the vibration speed sensor calibration method of this invention. It is a top view showing installation of the vibration speed sensor and acceleration sensor by a 3rd embodiment. It is a block diagram showing the scale factor of the acceleration sensor in which the input shaft was installed in the radial direction. It is a graph showing the example of a measurement voltage. In 2nd Embodiment or 3rd Embodiment, it is a perspective view which shows the example in which the vibration speed sensor and the acceleration sensor were installed on the same periphery. In 2nd Embodiment or 3rd Embodiment, it is a top view showing the example in which the vibration speed sensor and the acceleration sensor were installed on the same periphery. It is a perspective view which shows 4th Embodiment of the vibration speed sensor calibration apparatus which enforces the vibration speed sensor calibration method of this invention. It is a perspective view showing the structural example of the conventional vibration apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vibration speed sensor calibration apparatus 12 Rotation unit 14 Turntable 16 Base 18 Controller 28, 30 Acceleration sensor 34 Reference vibration speed sensor S Vibration speed sensor to be calibrated

Claims (8)

In the vibration speed sensor calibration method for calibrating the scale factor of the vibration speed sensor,
The vibration speed sensor is installed on a turntable coupled to a rotation drive source so that the input shaft thereof matches the rotation direction of the turntable,
The rotating table is rotated so as to vibrate at a certain rotation frequency, and a vibration speed that vibrates is input to the vibration speed sensor.
Obtain the output signal from the vibration speed sensor,
Calculating a scale factor from the acquired output signal;
A vibration speed sensor calibration method characterized by the above. Install the acceleration sensor on the turntable so that its input shaft matches the rotation direction of the turntable,
Obtaining an output signal from the acceleration sensor together with an output signal from the vibration speed sensor;
The calculation of the scale factor uses an output signal from the acquired acceleration sensor.
The vibration speed sensor calibration method according to claim 1. An acceleration sensor is installed on the turntable so that its input shaft is aligned with a radial direction perpendicular to the rotation direction of the turntable,
Obtaining an output signal from the acceleration sensor together with an output signal from the vibration speed sensor;
The calculation of the scale factor uses an output signal from the acquired acceleration sensor.
The vibration speed sensor calibration method according to claim 1.   4. The vibration speed sensor calibration method according to claim 2, wherein the scale factor is calculated using a scale factor calibrated in advance of the acceleration sensor.   5. The vibration speed sensor calibration method according to claim 2, wherein the acceleration sensor and the vibration speed sensor are arranged on the same circumference of a turntable. A calibrated reference vibration speed sensor is installed on the turntable so that its input shaft matches the rotation direction of the turntable,
Obtaining an output signal from the reference vibration speed sensor together with an output signal from the vibration speed sensor;
The calculation of the scale factor uses an output signal from the acquired reference vibration speed sensor and a pre-calibrated scale factor of the reference vibration speed sensor.
The vibration speed sensor calibration method according to claim 1.   The vibration speed sensor calibration method according to claim 6, wherein the reference vibration speed sensor and the vibration speed sensor are arranged on the same circumference of a turntable. A vibration speed sensor calibration apparatus for use in the vibration speed sensor calibration method according to any one of claims 1 to 7,
A vibration speed sensor calibration apparatus comprising: a rotation drive source; a turntable coupled to the rotation drive source; a base that rotatably supports the turntable; and a controller that controls a rotation frequency of the turntable.

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