JP2023156642A - Method for measuring acceleration sensor characteristics and device for measuring acceleration sensor characteristics - Google Patents

Abstract

To provide a method for measuring acceleration sensor characteristics with which it is possible to acquire characteristics with eccentric errors corrected, by a simple method.SOLUTION: Provided is a method for measuring acceleration sensor characteristics that involves attaching an acceleration sensor which is the object to be measured on a rotary table with its principal plane disposed in parallel to the direction of gravity and measuring the characteristics of the acceleration sensor. The method includes steps of: measuring the magnitude of the output of the acceleration sensor, using gravitational acceleration at the time of +1 gravitational acceleration; calculating the magnitude of the detection sensitivity of the acceleration sensor at the time of +1 gravitational acceleration; rotating the rotary table at an angular speed to generate the centrifugal acceleration of +1 gravitational acceleration and measuring acceleration that is the sum of centrifugal acceleration and gravitational acceleration detected by the acceleration sensor; removing only the centrifugal acceleration from the acceleration that is the sum of the centrifugal acceleration and gravitational acceleration; and estimating an eccentric error that is the error of attachment of the acceleration sensor to the rotary table.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for measuring characteristics of an acceleration sensor, and more particularly, the present invention relates to a method for measuring characteristics of an acceleration sensor, and more particularly, the present invention relates to a method for measuring characteristics of an acceleration sensor, and more particularly, it is possible to measure characteristics of an acceleration sensor by which characteristics are corrected for eccentricity error, which is an error in mounting an acceleration sensor as an object to be measured on a rotary table. Regarding the method. The present invention also relates to an acceleration sensor characteristic measuring device suitable for implementing the acceleration sensor characteristic measuring method of the present invention.

Acceleration sensors are widely used in a variety of applications. Acceleration sensors are extremely precise sensors, and there may be variations in characteristics among manufactured acceleration sensors. Therefore, it is necessary to measure and calibrate the characteristics of manufactured acceleration sensors one by one.

Patent Document 1 (Japanese Unexamined Patent Publication No. 5-164780) discloses a measuring method for an acceleration sensor. The method for measuring characteristics of an acceleration sensor disclosed in Patent Document 1 involves preparing a characteristics measuring device equipped with a rotating table that rotates in a direction perpendicular to the direction of gravity, attaching an acceleration sensor as an object to be measured to the rotating table, and then The rotary table is rotated to apply centrifugal force to the acceleration sensor, and the characteristics of the acceleration sensor are measured.

Patent Document 2 (Japanese Unexamined Patent Publication No. 2006-226680) discloses another acceleration sensor measurement method. The method for measuring characteristics of an acceleration sensor disclosed in Patent Document 2 involves rotating a main rotary table on which an acceleration sensor, which is an object to be measured, is attached, and a sub-rotation table for correcting eccentricity error, which is an error in attaching the acceleration sensor to the main rotary table. A characteristic measuring device equipped with a table is prepared, and the characteristics of the acceleration sensor are measured by rotating the main rotary table and applying centrifugal force to the acceleration sensor.

Japanese Patent Application Publication No. 5-164780 JP2006-226680A

When measuring the characteristics of an acceleration sensor using a rotary table, it is necessary to accurately attach the acceleration sensor to a predetermined position on the rotary table. However, it is difficult to accurately mount the acceleration sensor at a predetermined position on the rotary table, and eccentricity error, which is a mounting error, may occur. If the characteristics of the acceleration sensor are measured without correcting this eccentricity error, accurate characteristics cannot be obtained.

However, the method for measuring characteristics of an acceleration sensor disclosed in Patent Document 1 does not include a step of correcting eccentricity errors. Therefore, with the method for measuring characteristics of an acceleration sensor disclosed in Patent Document 1, it is difficult to obtain accurate characteristics of the acceleration sensor.

On the other hand, the method for measuring characteristics of an acceleration sensor disclosed in Patent Document 2 includes a step of correcting eccentricity errors, and enables highly accurate characteristics measurement of the acceleration sensor. However, the method for measuring characteristics of an acceleration sensor disclosed in Patent Document 2 has a problem in that it requires an extremely complicated and expensive measuring device that includes a main rotary table and a sub-rotary table.

Therefore, the present invention provides a simple method for obtaining acceleration characteristics that corrects the eccentricity error of the acceleration sensor to the rotary table, which is the object to be measured, without requiring a complicated and expensive measuring device. The purpose of this invention is to provide a method for measuring sensor characteristics.

Another object of the present invention is to provide an acceleration sensor characteristic measuring device suitable for implementing the acceleration sensor characteristic measuring method of the present invention.

In order to solve the above-mentioned problems, a method for measuring characteristics of an acceleration sensor according to an embodiment of the present invention mounts an acceleration sensor, which is an object to be measured, on a rotary table whose main surface is arranged parallel to the direction of gravity. , a method for measuring the characteristics of an acceleration sensor, which includes the steps of measuring the magnitude of the output of the acceleration sensor when the gravitational acceleration is +1 using gravitational acceleration; the step of calculating the magnitude of the detection sensitivity of the acceleration sensor when a step of extracting only centrifugal acceleration from the combined acceleration of centrifugal acceleration and gravitational acceleration; and a step of estimating eccentricity error, which is an error in mounting the acceleration sensor on the rotary table. shall be held.

In addition, in order to solve the above-mentioned problems, an acceleration sensor characteristic measuring device according to an embodiment of the present invention is arranged such that the main surface thereof is parallel to the direction of gravity, on which the acceleration sensor that is the object to be measured can be attached. An apparatus for measuring characteristics of an acceleration sensor, comprising a rotary table, a computer, and a program for operating the computer, wherein the computer operated by the program uses gravitational acceleration to measure the acceleration when the gravitational acceleration is +1. It is assumed that the magnitude of the output of the acceleration sensor is measured.

Note that the computer operated by the program of the characteristic measuring device may calculate the detection sensitivity of the acceleration sensor when the gravitational acceleration is +1. Further, the computer operated by the program of the characteristic measuring device rotates the rotary table at an angular velocity that generates centrifugal acceleration of +1 gravitational acceleration, and calculates the combined acceleration of centrifugal acceleration and gravitational acceleration detected by the acceleration sensor. It may be something to be measured. Further, the computer operated by the program of the characteristic measuring device may estimate an eccentricity error, which is an error in attaching the acceleration sensor to the rotary table. Further, the computer operated by the program of the characteristic measuring device may measure the magnitude of the output of the acceleration sensor at a desired acceleration after correcting the eccentricity error ε.

According to a method for measuring characteristics of an acceleration sensor according to an embodiment of the present invention, it is possible to correct eccentricity errors and measure highly accurate characteristics of an acceleration sensor in a simple manner without requiring a complicated measuring device. can be measured.

Moreover, according to the acceleration sensor characteristic measuring device according to one embodiment of the present invention, the acceleration sensor characteristic measuring method of the present invention can be easily carried out.

1 is an explanatory diagram (schematic diagram) of a characteristic measuring device 100. FIG. FIG. 2 is an explanatory diagram (schematic diagram) of an acceleration sensor 200 that is an object to be measured. 2 is an explanatory diagram (schematic diagram) showing a method of attaching an acceleration sensor 200 to a rotary table 1 of a characteristic measuring device 100. FIG. It is a graph showing the output Sout (±1g). FIG. 3 is a flow diagram showing steps included in a method for measuring characteristics of an acceleration sensor according to an embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated with drawing.

Note that each embodiment is an exemplary embodiment of the present invention, and the present invention is not limited to the content of the embodiment. Further, it is also possible to implement the contents described in different embodiments in combination, and the implementation contents in that case are also included in the present invention. In addition, the drawings are intended to aid understanding of the specification and may be drawn schematically, and the drawn components or the dimensional ratios between the components may be different from those described in the specification. The proportions of those dimensions may not match. In addition, there are cases where constituent elements described in the specification are omitted in the drawings or drawn with their numbers omitted.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for measuring characteristics of an acceleration sensor according to the present invention will be described below with reference to the drawings.

The method for measuring characteristics of an acceleration sensor according to the present embodiment proceeds through the following steps.

[Preparation of characteristic measuring device 100]
FIG. 1 shows a characteristic measuring device 100 used in the acceleration sensor characteristic measuring method of this embodiment. However, the characteristic measuring device 100 is merely an example, and the characteristic measuring device that can be used in the acceleration sensor characteristic measuring method of the present invention is not limited to the characteristic measuring device 100.

The characteristic measuring device 100 includes a rotary table 1. In this embodiment, the rotary table 1 has a disk shape with a uniform thickness. The rotary table 1 has a first main surface 1a and a second main surface 1b that face each other on the front and back. Although the material of the rotary table 1 is arbitrary, aluminum can be used, for example.

The rotary table 1 has a first main surface 1a and a second main surface 1b arranged parallel to the direction of gravity. Therefore, the rotary table 1 rotates within a vertical plane.

The rotary table 1 has a first main surface 1a formed with mounting means 2 for mounting an acceleration sensor 200, which will be described later, as an object to be measured. The attachment means 2 is formed near the outer edge of the first main surface 1a. The structure of the attachment means 2 is arbitrary, and various methods can be adopted.

The rotating table 1 has a rotating shaft 3 attached to the center of the second main surface 1b. The axis of the rotating shaft 3 is defined as the rotating axis RA of the rotating table 1.

A servo motor 4 is attached to the rotating shaft 3 as a rotational drive device for rotating the rotating shaft 3. However, the type of rotary drive device is arbitrary and is not limited to the servo motor 4.

The characteristic measuring device 100 includes a computer 5. The characteristic measuring device 100 includes a program 6 that causes a computer 5 to operate. The computer 5 operated by the program 6 controls the rotation of the servo motor 4, measures the output of the acceleration sensor 200, and records data such as the output of the acceleration sensor 200 on a recording medium or the like.

The characteristic measuring device 100 having the above configuration can rotate the rotary table 1 in a desired rotation direction at a desired angular velocity ω. However, in this embodiment, the rotary table 1 will be described as rotating clockwise.

[Preparation of acceleration sensor 200]
Next, the acceleration sensor 200, which is the object to be measured in this embodiment, is prepared. FIG. 2 shows an acceleration sensor 200.

The acceleration sensor 200 in this embodiment includes a cantilevered beam 21. A weight 22 is provided at the tip of the beam 21. Acceleration sensor 200 has a sensitivity axis SA. The sensitivity axis SA passes through the weight 22 and extends in the direction in which the beam 21 is deflected. However, the structure of the acceleration sensor that is the object to be measured is arbitrary, and is not limited to the acceleration sensor 200.

Acceleration sensor 200 can detect acceleration in the direction of sensitivity axis SA. The acceleration detected by the acceleration sensor 200 is processed by the computer 5 of the characteristic measuring device 100.

[Attachment of acceleration sensor 200 to characteristic measuring device 100]
Next, as shown in FIG. 3, the acceleration sensor 200 is attached to the characteristic measuring device 100.

In this embodiment, the acceleration sensor 200 is attached to the attachment means 2 of the rotary table 1 so that the sensitivity axis SA passes through the rotation axis RA of the rotary table 1.

When the acceleration sensor 200 is mounted on the rotary table 1 so that the sensitivity axis SA passes through the rotation axis RA, when the acceleration sensor 200 is located directly to the right from the rotation axis RA in FIG. 200 no longer detects gravitational acceleration at all. Therefore, this direction is defined as the reference direction RD.

The angle formed between the reference direction RD and the direction in which the acceleration sensor 200 exists with respect to the rotation axis RA is defined as the mounting angle θ of the acceleration sensor 200. The mounting angle θ has a positive value in the clockwise direction from the reference direction RD, and a negative value in the counterclockwise direction from the reference direction RD.

Acceleration sensor 200 is attached to rotary table 1 such that weight 22 is located at a distance L from rotation axis RA.

However, when attaching the acceleration sensor 200 to the rotary table 1, it is difficult to place the weight 22, which is the detection part, at an accurate distance L from the rotation axis RA, and an eccentric error ε, which is an attachment error, occurs. There are cases.

The main purpose of the acceleration sensor characteristic measuring method of the present invention is to obtain this eccentricity error ε, correct this eccentricity error ε, and then accurately obtain the characteristics of the acceleration sensor.

[About acceleration a detected by acceleration sensor 200]
When the rotary table 1 to which the acceleration sensor 200 is attached is rotated clockwise at an angular velocity ω, the acceleration sensor 200 detects the acceleration a shown in Equation 1.

In equation 1,
a=acceleration (m/s ² )
L = distance (m)
ε = Eccentricity error (m)
ω = angular velocity (rad/s)
g = gravitational acceleration (≒9.81 (m/s ² ))
θ=Installation angle (rad)
t=elapsed time (s)
It is.

In Equation 1, (L+ε)×ω ² is a component of the centrifugal acceleration detected by the acceleration sensor 200. In Equation 1, g sin (ωt+θ) is a component of the gravitational acceleration detected by the acceleration sensor 200. That is, the acceleration sensor 200 attached to the rotating rotary table 1 detects an acceleration a that is a combination of centrifugal acceleration and gravitational acceleration.

[Measurement of output Sout (+1 g) of acceleration sensor 200 when detecting acceleration a (+1 g)]
As described above, the acceleration a detected by the acceleration sensor 200 is output in the computer 5 of the characteristic measuring device 100 after being converted into, for example, a voltage (V). Let the output be Sout.

The relationship between the acceleration a and the output Sout is expressed by Equation 2.

In Equation 2, Ssens is the detection sensitivity. The Ssens detection sensitivity is a value specific to each acceleration sensor 200. Even with the same acceleration sensor 200, the detection sensitivity Ssens differs depending on the individual. The detection sensitivity Ssens may change depending on the magnitude of the detected acceleration a.

When the acceleration sensor 200 detects +1g (approximately 9.81 (m/s ² )) equal to the gravitational acceleration, the acceleration is a (+1g), the detection sensitivity is Ssens (+1g), and the output is Sout (+1g). . The acceleration a (+1g), the detection sensitivity Ssens (+1g), and the output Sout (+1g) have the relationship shown in Equation 3.

The detection sensitivity Ssens (+1g) is expressed by Equation 4.

In Equation 4, acceleration a (+1 g) is gravitational acceleration and is approximately 9.81 (m/s ² ). Since Sout (+1g) of this acceleration sensor 200 is unknown, it is derived by actual measurement.

When the rotary table 1 is stopped, ω=0, so Equation 1 indicating the acceleration a can be replaced with Equation 5.

Equation 5 does not include the eccentricity error ε. Therefore, when the rotary table 1 is stopped, the acceleration a is not affected by the eccentricity error ε.

In FIG. 3, when the acceleration sensor 200 is stopped in the direction directly to the right (reference direction RD) when viewed from the rotation axis RA, the mounting angle θ=0πrad, and the acceleration sensor 200 outputs Sout (0 g). do.

In FIG. 3, when the acceleration sensor 200 is stopped in the direction directly below when viewed from the rotation axis RA, the mounting angle θ=1/2πrad, and the acceleration sensor 200 outputs Sout (+1 g).

In FIG. 3, when the acceleration sensor 200 is stopped in the direction directly to the left when viewed from the rotation axis RA, the mounting angle θ=1πrad, and the acceleration sensor 200 outputs Sout (0 g).

In FIG. 3, when the acceleration sensor 200 is stopped directly above the rotation axis RA, the mounting angle θ=3/2πrad, and the acceleration sensor 200 outputs Sout (−1 g).

When the output Sout is measured while rotating the rotary table 1 at a low speed where the centrifugal acceleration is sufficiently small compared to 1 g, or when the output Sout is measured when the rotary table 1 is rotated intermittently and stopped. , the output Sout is shown in FIG.

In FIG. 4, the X-axis shows the mounting angle θ, and the Y-axis shows the output Sout (±1g) in the range from -1g to +1g. Note that the Y-axis output Sout (±1 g) is, for example, a voltage (V) as described above, but no scale is shown in FIG. 4. The output Sout (±1g) draws a sine curve.

In order to obtain a more accurate sine curve of the output Sout (±1 g), it is preferable to use the following method, for example. First, the output at the mounting angle θ=1/2πrad is measured. Next, the output at 10 points before and after the mounting angle θ=1/2πrad is measured. Then, by fitting the output data of 11 points including these to the sine curve, a more accurate sine curve of the output Sout (±1 g) can be obtained.

In the actually measured output Sout (±1 g), the output when the mounting angle θ=1/2πrad is defined as the output Sout (+1 g). The output Sout (+1g) matches the amplitude of the sine curve shown in FIG.

As described above, it was possible to measure the output Sout (+1 g) when the acceleration sensor 200 detected the acceleration a (+1 g).

Furthermore, since the output Sout (+1 g) can be measured, the detection sensitivity Ssens (+1 g) of the acceleration sensor 200 can be calculated as a real number from Equation 4.

The output Sout (+1 g) of the acceleration sensor 200 when the acceleration is a (+1 g) is stored in the recording medium. Additionally, the detection sensitivity Ssens (+1 g) of the acceleration sensor 200 may be stored in the recording medium. Any recording medium may be used to record the output Sout (+1g) and the detection sensitivity Ssens (+1g). A specific IC (not shown) linked to this acceleration sensor 200 may be prepared, and the information may be recorded on a recording medium included in the IC. Alternatively, it may be recorded on a recording medium included in the computer 5 of the characteristic measuring device 100, or

[Estimation of eccentricity error ε]
Next, the magnitude of the eccentricity error ε, which is the error in attaching the acceleration sensor 200 to the rotary table 1 in this embodiment, is estimated.

First, the rotary table 1 is rotated at an angular velocity ω (+1 g) that causes the acceleration sensor 200 attached to the rotary table 1 to generate a centrifugal acceleration of an acceleration a (+1 g). The angular velocity ω (+1g) can be obtained from Equation 6. However, Equation 6 does not include the eccentricity error ε, and the acceleration sensor 200 is assumed to be attached to the rotary table 1 at an accurate distance L from the rotation axis RA, and the angular velocity ω(+1 g ). Note that when the rotary table 1 is rotated at an angular velocity ω (+1 g), the acceleration sensor 200 detects not only centrifugal acceleration but also gravitational acceleration.

When the angular velocity ω (+1g) is determined from Equation 6, Equation 7 is obtained.

In Equation 7, L is a predetermined distance from the rotation axis RA to which the acceleration sensor 200 is to be attached. In Equation 7, acceleration a (+1 g) is gravitational acceleration and is approximately 9.81 (m/s ² ).

When the rotary table 1 is rotated at an angular velocity ω (+1 g), the acceleration sensor 200 detects the acceleration a shown in Equation 8 if there is no eccentricity error ε.

Based on Equation 8, the average value of acceleration a (indicated by a horizontal bar drawn above "a") during a period of n, which is an integral multiple of period T, is calculated as Equation 9. Note that in order to obtain the average value, the acceleration a may be integrated over a period n that is an integral multiple of the period T, and then divided by nT.

As can be seen from Equation 9, the average value of the acceleration a during a period of integral multiple n of the period T matches the centrifugal acceleration component when the angular velocity ω (+1 g), excluding the gravitational acceleration component.

As a result, when there is no eccentricity error ε, the average value of Sout during a period of n which is an integer multiple of the period T is expressed by Equation 10.

In the case where there is no eccentricity error ε, the average value of Sout during a period of integral multiple n of the period T matches the output Sout (+1 g) of the acceleration sensor 200 when the acceleration is a (+1 g). The output Sout (+1g) has already been obtained using gravitational acceleration and recorded on the recording medium. Therefore, equation 10 can be replaced with equation 11.

The above is a case where there is no eccentricity error ε and the acceleration sensor 200 is mounted at an accurate distance L from the rotation axis RA. However, in reality, an eccentricity error ε may occur, and in that case, the acceleration A applied to the sensor during actual measurement does not match the acceleration a when there is no eccentricity error ε.

When the rotary table 1 is rotated at an angular velocity ω (+1 g), the acceleration A detected by the acceleration sensor 200 and applied to the sensor during actual measurement including the eccentricity error ε is shown in Equation 12.

Based on Equation 12, when calculating the average value of acceleration A applied to the sensor during actual measurement (indicated by a symbol with a horizontal bar drawn above "A") during a period of integral multiple n of period T, Equation 13 is obtained. Become.

As a result, the actually measured average value of Sout during a period of n, which is an integral multiple of the period T, including the eccentricity error ε, is expressed by Equation 14.

In Equation 11 shown above, the output Sout (+1g) has already been obtained using gravitational acceleration and recorded on the recording medium. The detection sensitivity Ssens (+1 g) of the acceleration sensor 200 is known from Equation 4. L is a predetermined distance from the rotation axis RA to which the acceleration sensor 200 is to be attached. The angular velocity ω (+1 g) is an angular velocity that causes centrifugal acceleration of acceleration a (+1 g) to be generated in the acceleration sensor 200 attached to the rotary table 1, and is known from Equation 7.

In Equation 14, the average value of Sout during a period of n, which is an integral multiple of the period T, is obtained by actual measurement. The detection sensitivity Ssens (+1 g) of the acceleration sensor 200 is known from Equation 4. L is a predetermined distance from the rotation axis RA to which the acceleration sensor 200 is to be attached. The angular velocity ω (+1 g) is an angular velocity that causes centrifugal acceleration of acceleration a (+1 g) to be generated in the acceleration sensor 200 attached to the rotary table 1, and is known from Equation 7.

In Equations 11 and 14, only the eccentricity error ε is unknown. From Equations 11 and 14, the eccentricity error ε is determined by Equation 15.

Equation 15 can be replaced with Equation 16.

As described above, it was possible to estimate (obtain) the eccentricity error ε, which is the attachment error of the acceleration sensor 200 to the rotary table 1, as a real number in this embodiment.

[Measurement of output Sout(x) at acceleration a(x) with eccentricity error ε corrected]
Next, the output Sout(x) at the acceleration a(x) of the acceleration sensor 200 with the eccentricity error ε corrected is measured. Note that this measurement is performed without changing the mounting position of the acceleration sensor 200 on the rotary table 1 from before.

For example, the output (+2 g) of the acceleration a (+2 g) of the acceleration sensor 200 can be measured by the following method.

First, the rotary table 1 is rotated at an angular velocity ω (+2 g) that causes the acceleration sensor 200 attached to the rotary table 1 to generate a centrifugal acceleration of an acceleration a (+2 g). The angular velocity ω(+2g) can be obtained from Equation 17.

In Equation 17, acceleration a (+2g) is twice the gravitational acceleration. L is a predetermined distance from the rotation axis RA to which the acceleration sensor 200 is to be attached. The eccentricity error ε is known.

Next, Sout (+2g) is actually measured, and the average value over a period of n, which is an integral multiple of the period T, is determined. This average value excludes the gravitational acceleration component and shows only the centrifugal acceleration component when the angular velocity is ω (+2 g). The average value during a period of n, which is an integral multiple of the period T, is defined as the output Sout (+2 g) when the acceleration of the acceleration sensor 200 is a (+2 g). The output Sout (+2 g) of the acceleration sensor 200 when the acceleration is a (+2 g) is recorded on a recording medium.

Using a similar method, the output Sout (+3g) of this acceleration sensor 200 when acceleration a (+3g), the output Sout (+4g) when acceleration a (+4g), and the output Sout (+5g) when acceleration a (+5g) are obtained. )... and record it on a recording medium. Note that the acceleration a to be measured is not limited to an integral multiple of the gravitational acceleration, and any necessary magnitude of acceleration a can be measured.

As described above, the output Sout(x) at the acceleration a(x) of this acceleration sensor 200 with the eccentricity error ε corrected could be measured and recorded on the recording medium. However, X is the magnitude of acceleration to be measured.

[Summary of method for measuring characteristics of acceleration sensor of this embodiment]
The method for measuring the characteristics of the acceleration sensor of this embodiment explained above can be summarized as shown in FIG. 5. However, FIG. 5 only shows important steps.

The acceleration sensor characteristic measuring method of this embodiment includes the step of measuring the output Sout (+1 g) of the acceleration sensor 200 at acceleration a (+1 g) using gravitational acceleration. Instead of the acceleration a (+1 g), the output Sout (-1 g) of the acceleration sensor 200 at the acceleration a (-1 g) may be measured. In this case as well, since the absolute values of the outputs are the same, it is assumed that the output Sout (+1 g) of the acceleration sensor 200 at the acceleration a (+1 g) is measured.

The acceleration sensor characteristic measuring method of this embodiment includes the step of calculating the detection sensitivity Ssens (+1 g) of the acceleration sensor 200 when acceleration a (+1 g) is detected.

The method for measuring the characteristics of the acceleration sensor of this embodiment is to rotate the rotary table 1 at an angular velocity ω (+1 g) that causes the acceleration sensor 200 attached to the rotary table 1 to generate a centrifugal acceleration of acceleration a (+1 g), The method includes a step of measuring a combination of acceleration and gravitational acceleration. Note that the measured acceleration includes an eccentricity error ε.

The method for measuring characteristics of an acceleration sensor according to the present embodiment includes a step of extracting only centrifugal acceleration from a combination of centrifugal acceleration and gravitational acceleration. Note that the extracted centrifugal acceleration includes an eccentricity error ε.

The acceleration sensor characteristic measuring method of this embodiment includes a step of estimating eccentricity error ε.

The acceleration sensor characteristic measuring method of this embodiment includes the step of correcting the eccentricity error ε and then measuring the output Sout(X) at a desired acceleration a(X). Note that X is the magnitude of acceleration to be measured.

According to the acceleration sensor characteristic measuring method of this embodiment, which includes the above steps, the characteristics of the acceleration sensor 200, which is the object to be measured, can be measured after correcting the eccentricity error ε. The characteristic is, for example, the magnitude of the output Sout(X) of the acceleration sensor 200 at a desired acceleration a(X). Alternatively, the characteristic is the magnitude of the detection sensitivity Ssens(X) of the acceleration sensor 200 at a desired acceleration a(X).

[About the characteristic measuring device 100]
The characteristic measuring device 100 used in the method for measuring characteristics of an acceleration sensor according to this embodiment will be briefly described.

As shown in FIG. 1, the characteristic measuring device 100 includes a rotary table 1 and a servo motor 4, which is a rotational drive device that rotates the rotary table 1. The rotary table 1 and the servo motor 4 are connected by a rotary shaft 3. A mounting means 2 is formed on the rotary table 1 to which an acceleration sensor 200, which is an object to be measured, can be mounted.

The characteristic measuring device 100 includes a computer 5 and a program 6 that operates the computer 5. The computer 5 can control the rotation of the rotary table 1, measure the output of the acceleration sensor 200, and record data such as the output of the acceleration sensor 200 on a recording medium or the like.

The method for measuring characteristics of an acceleration sensor and the device for measuring characteristics of an acceleration sensor according to the embodiment have been described above. However, the present invention is not limited to the content described above, and various changes can be made in accordance with the spirit of the invention.

The method for measuring the characteristics of an acceleration sensor according to an embodiment of the present invention is as described in the "Means for Solving the Problems" section.

It is also preferable that the method for measuring characteristics of an acceleration sensor includes the step of correcting the eccentricity error and then measuring the magnitude of the output of the acceleration sensor at a desired acceleration. In this case, highly accurate output of the acceleration sensor can be obtained.

It is also preferable to include the step of recording the magnitude of the output on a recording medium. It is also preferable to include a step of recording the magnitude of the output of the acceleration sensor at +1 gravitational acceleration on the recording medium. It is also preferable to include a step of recording the detection sensitivity of the acceleration sensor at +1 gravitational acceleration on a recording medium. As the recording medium, for example, a recording medium included in an IC that is linked to an acceleration sensor that is an object to be measured can be used. Alternatively, a recording medium included in a computer of the characteristic measuring device can be used as the recording medium.

The acceleration sensor characteristic measuring device according to one embodiment of the present invention is as described in the "Means for Solving the Problems" section.

In this acceleration sensor characteristic measuring device, it is also preferable that only centrifugal acceleration is extracted from the combined acceleration of centrifugal acceleration and gravitational acceleration by a computer operated by a program.

It is also preferable that the acceleration sensor characteristic measuring device includes a recording medium for recording data.

Further, it is also preferable that the acceleration sensor characteristic measuring device includes a servo motor as a rotation drive device for rotating the rotary table. In this case, the rotary table can be rotated with high precision.

Furthermore, a rotary encoder is attached to the rotating axis of the rotating table so that the angle of the rotating table can be measured. It is also preferable to output a Z-phase pulse. In this case, the period of the sine output of the acceleration sensor can be measured more accurately.

[Additional notes]
<1>
A method for measuring characteristics of an acceleration sensor, the method comprising: attaching an acceleration sensor as an object to be measured to a rotary table whose main surface is arranged parallel to the direction of gravity, and measuring the characteristics of the acceleration sensor;
using gravitational acceleration to measure the magnitude of the output of the acceleration sensor when the gravitational acceleration is +1;
calculating the detection sensitivity of the acceleration sensor when the gravitational acceleration is +1;
rotating the rotary table at an angular velocity that generates a centrifugal acceleration of +1 gravitational acceleration, and measuring the combined acceleration of the centrifugal acceleration and gravitational acceleration detected by the acceleration sensor;
extracting only centrifugal acceleration from the combined acceleration of centrifugal acceleration and gravitational acceleration;
A method for measuring characteristics of an acceleration sensor, including the step of estimating an eccentricity error, which is an error in mounting the acceleration sensor on the rotary table.
<2>
The method for measuring characteristics of an acceleration sensor according to <1>, including the step of measuring the magnitude of the output of the acceleration sensor at a desired acceleration after correcting the eccentricity error.
<３>
The method for measuring characteristics of an acceleration sensor according to <1> or <2>, including the step of recording the magnitude of the output on a recording medium.
<４>
The method for measuring characteristics of an acceleration sensor according to any one of <1> to <3>, including the step of recording the magnitude of the output of the acceleration sensor at the +1 gravitational acceleration on a recording medium.
<5>
The method for measuring characteristics of an acceleration sensor according to any one of <1> to <4>, comprising recording on a recording medium the magnitude of detection sensitivity of the acceleration sensor at the +1 gravitational acceleration. .
<6>
A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
A characteristic measuring device for an acceleration sensor, wherein the magnitude of the output of the acceleration sensor at +1 gravitational acceleration is measured using gravitational acceleration.
<7>
A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
A characteristic measuring device for an acceleration sensor, wherein a magnitude of detection sensitivity of the acceleration sensor at +1 gravitational acceleration is calculated.
<8>
a rotating rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as an object to be measured can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
An acceleration sensor characteristic measuring device in which the rotary table is rotated at an angular velocity that generates a centrifugal acceleration of +1 gravitational acceleration, and the acceleration that is a combination of centrifugal acceleration and gravitational acceleration detected by the acceleration sensor is measured.
<9>
By the computer operated by the program,
The acceleration sensor characteristic measuring device according to <8>, wherein only centrifugal acceleration is extracted from the combination of centrifugal acceleration and gravitational acceleration.
<10>
A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
An acceleration sensor characteristic measuring device in which an eccentricity error, which is an error in mounting the acceleration sensor on the rotary table, is estimated.
<11>
A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
A characteristic measuring device for an acceleration sensor, wherein the magnitude of the output of the acceleration sensor at a desired acceleration is measured after correcting the eccentricity error ε.
<12>
The acceleration sensor characteristic measuring device according to any one of <6> to <11>, comprising a recording medium for recording data.
<13>
The acceleration sensor characteristic measuring device according to any one of <6> to <12>, comprising a servo motor as a rotational drive device for rotating the rotary table.
<14>
A rotary encoder is attached to the rotating shaft of the rotating table so as to measure the angle of the rotating table,
Any one of <6> to <13>, wherein the rotary encoder outputs a Z-phase pulse when the direction of the sensitivity axis of the acceleration sensor attached to the rotary table becomes parallel to the direction of gravity. An apparatus for measuring characteristics of an acceleration sensor described in one of the above.

1...Rotary table 2...Mounting means 3...Rotating shaft 4...Servo motor 5...Computer 6...Program 100...Characteristics measuring device 200...Acceleration sensor (measured thing)

Claims (14)

A method for measuring characteristics of an acceleration sensor, the method comprising: attaching an acceleration sensor as an object to be measured to a rotary table whose main surface is arranged parallel to the direction of gravity, and measuring the characteristics of the acceleration sensor;
using gravitational acceleration to measure the magnitude of the output of the acceleration sensor when the gravitational acceleration is +1;
calculating the detection sensitivity of the acceleration sensor when the gravitational acceleration is +1;
rotating the rotary table at an angular velocity that generates a centrifugal acceleration of +1 gravitational acceleration, and measuring the combined acceleration of the centrifugal acceleration and gravitational acceleration detected by the acceleration sensor;
extracting only centrifugal acceleration from the combined acceleration of centrifugal acceleration and gravitational acceleration;
estimating an eccentricity error, which is an error in attaching the acceleration sensor to the rotary table;
How to measure the characteristics of an acceleration sensor. a step of measuring the magnitude of the output of the acceleration sensor at a desired acceleration after correcting the eccentricity error;
A method for measuring characteristics of an acceleration sensor according to claim 1. recording the magnitude of the output on a recording medium;
A method for measuring characteristics of an acceleration sensor according to claim 2. recording the magnitude of the output of the acceleration sensor at the +1 gravitational acceleration on a recording medium;
A method for measuring characteristics of an acceleration sensor according to claim 1. a step of recording the detection sensitivity of the acceleration sensor at the +1 gravitational acceleration on a recording medium;
A method for measuring characteristics of an acceleration sensor according to claim 1. A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
Using gravitational acceleration, the magnitude of the output of the acceleration sensor at +1 gravitational acceleration is measured;
Acceleration sensor characteristic measuring device. A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
The magnitude of the detection sensitivity of the acceleration sensor at +1 gravitational acceleration is calculated;
Acceleration sensor characteristic measuring device. a rotating rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as an object to be measured can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
The rotary table is rotated at an angular velocity that generates a centrifugal acceleration of +1 gravitational acceleration, and the combined acceleration of the centrifugal acceleration and gravitational acceleration detected by the acceleration sensor is measured.
Acceleration sensor characteristic measuring device. By the computer operated by the program,
Only the centrifugal acceleration is extracted from the combined acceleration of the centrifugal acceleration and the gravitational acceleration.
The acceleration sensor characteristic measuring device according to claim 8. A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
An eccentricity error is estimated, which is an error in attaching the acceleration sensor to the rotary table.
Acceleration sensor characteristic measuring device. A rotary table whose main surface is arranged parallel to the direction of gravity, on which an acceleration sensor as a measured object can be attached;
computer and
An acceleration sensor characteristic measuring device comprising a program for operating the computer,
By the computer operated by the program,
After correcting the eccentricity error ε, the magnitude of the output of the acceleration sensor at a desired acceleration is measured.
Acceleration sensor characteristic measuring device. Equipped with a recording medium for recording data,
An apparatus for measuring characteristics of an acceleration sensor according to any one of claims 6 to 11. A servo motor is provided as a rotation drive device for rotating the rotary table.
An apparatus for measuring characteristics of an acceleration sensor according to any one of claims 6 to 11. A rotary encoder is attached to the rotating shaft of the rotating table so as to measure the angle of the rotating table,
The rotary encoder outputs a Z-phase pulse when the direction of the sensitivity axis of the acceleration sensor attached to the rotary table becomes parallel to the direction of gravity.
An apparatus for measuring characteristics of an acceleration sensor according to any one of claims 6 to 11.

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