JPH05164780A - Method and device for measuring performance of acceleration sensor - Google Patents

Abstract

PURPOSE:To achieve measurement as an acceleration region in a wide range by giving a sensor a centrifugal force in a direction which crosses a direction or gravity and by comparing the given centrifugal force with an acceleration which the sensor measured. CONSTITUTION:An upper surface 45 of a measurement arm 44 is allowed to cross a direction C of gravity and an acceleration sensor 1 is fitted to a reference surface 47 of a sample stand 46 so that a measurement axis crosses the direction C. The sensor indicates gravitational acceleration to be 0G. A cord 49 of the sensor 1 is connected 50 to a control box 48. When a drive motor 67 is operated, a rotary axis 19 is driven, the arm 44 is rotated within a horizontal plane, and then an acceleration consisting of centrifugal force is given to the sensor 1 from a direction B which crosses the direction C. An output from the sensor 1 is output to a proper comparison means through a slip ring 39 and a rotary speed of the axis 19 is output to a comparison means by an encoder 52. A comparison means obtains an actual acceleration from a given centrifugal force, compares it with a value of acceleration which is detected by the sensor 1 for evaluating performance of the sensor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for measuring the performance of an acceleration sensor, and more particularly to a method and apparatus for measuring the performance of an acceleration sensor capable of measuring the output characteristics of the acceleration sensor over a wide range.

[0002]

2. Description of the Related Art Generally, an acceleration sensor is often used in, for example, an automobile and the like, and during a turning operation during traveling, an acceleration due to a centrifugal force is applied in a direction orthogonal to the traveling direction of the vehicle body (lateral direction of the vehicle body). When the vehicle body leans by acting, the acceleration acting in the lateral direction of the vehicle body is detected, and the acceleration detecting means of the control mechanism is used to stiffen the suspension in the vehicle body leaning direction.

Further, the conventional acceleration sensor 1 will be described. As shown in FIG.
It has a structure (differential capacitor) in which two capacitors in which a movable electrode 3 having a spring function is disposed between fixed electrodes 2 and 2 facing each other are stacked (differential capacitor). Displacement in the direction of the middle arrow A changes the capacities of the two capacitors, and the acceleration is detected by the relative capacities of the two capacitors.

Next, an acceleration sensor performance measuring device 4 for measuring the output characteristics of the conventional acceleration sensor 1 will be described with reference to FIG.

As shown in FIG. 6, in a conventional performance measuring device 4 for an acceleration sensor, a base frame 5 is horizontally arranged in the lower part in a direction orthogonal to the direction of gravity, and 2 is provided on the base frame 5. The individual side frames 6 and 6 are erected parallel to each other. At appropriate positions between the side frames 6 and 6, a flat plate shape or a drum shape is formed so as to extend in parallel with the base frame 5. A sample support base 7 is horizontally rotatably mounted on a rotary shaft 7a. And
The sample support base 7 is rotated by a stepping motor 8 fixed to one side frame 6 and can be held at an arbitrary angle. Further, the acceleration sensor 1 can be detachably mounted on the side surface of the sample support base 7 with its thickness direction (direction of the measurement axis) aligned with the direction orthogonal to the rotation axis 7a.

Next, a method of measuring the performance of the acceleration sensor 1 by the above-described conventional performance measuring device 4 for the acceleration sensor will be described with reference to FIGS. 6 to 9.

Conventionally, the gravitational acceleration is used for the measurement. As shown in FIG. 6, the acceleration sensor 1 is attached to the side surface of the sample support base 7 by an appropriate method, and then, as shown in FIG. The stepping motor 8 is driven according to the acceleration at which the angle of the support base 7 is to be measured, and is fixed at a predetermined angle θ.

That is, the arrow B in the figure by the acceleration sensor 1
The direction of the measurement axis indicated by is arranged at an angle θ (hereinafter, referred to as an axis angle) with respect to the gravity direction indicated by an arrow C in the figure, in other words, the acceleration sensor 1 has a gravitational acceleration × a cosine value of an axis angle (1G × cos θ), and the output from the acceleration sensor 1, for example, the voltage output is measured by a known measuring means (not shown).

Therefore, as shown in FIG. 8, when the direction B of the measurement axis matches the direction C of gravity, θ = 0 degree,
Acceleration of 1G can be measured, and as shown in FIG. 9, when the direction B of the measurement axis is perpendicular to the gravity direction C, θ = 90 degrees, and 0G acceleration can be measured.

Then, by changing this axis angle arbitrarily,
The performance of the acceleration sensor 1 is measured by measuring the output of the acceleration sensor 1 at each axis angle and comparing the applied acceleration with an appropriate comparison means.

[0011]

However, in the performance measuring method of the acceleration sensor 1 in the above-described performance measuring device 4 for an acceleration sensor of the related art, in order to measure the acceleration by applying the gravitational acceleration, the acceleration of up to 1 G is required. There was a problem that you could only measure

Further, in order to perform measurement by giving an axis angle to the acceleration sensor 1 with respect to the direction of gravity, the acceleration sensor 1 must be tilted at an arbitrary angle each time measurement is performed, and the tilt angle of the acceleration sensor 1 is inevitable. There is a problem in that the output changes due to various influences generated by changing, such as the sensitivity of another axis. Further, in order to measure the linearity of the output characteristic of the acceleration sensor 1, it is necessary to detect the tilt angle with high accuracy and accuracy, and the tilt angle detection means becomes expensive and the economical burden increases. there were.

The present invention has been made in view of these points, and overcomes the above-mentioned problems in the conventional ones.
An object of the present invention is to provide an acceleration sensor performance measuring method and device which have a simple structure, have high reliability, and can perform measurement in a wide range of acceleration regions exceeding gravitational acceleration.

[0014]

In order to achieve the above-mentioned object, the performance measuring method for an acceleration sensor according to the present invention as defined in claim 1 is such that an acceleration to be measured with respect to the acceleration sensor is a direction orthogonal to the direction of gravity. Is applied, and the performance is measured by comparing the applied centrifugal force with the acceleration measured by the acceleration sensor.

According to a second aspect of the present invention, there is provided an acceleration sensor performance measuring apparatus, wherein a centrifugal force imparting means for imparting a centrifugal force to a mounted acceleration sensor in a direction orthogonal to a gravity direction, and the acceleration sensor. It is characterized by having an applied centrifugal force measuring means for obtaining the centrifugal force applied to the sensor and a sensor output extracting means for extracting an output in response to the acceleration measured by the acceleration sensor.

[0016]

By operating the acceleration sensor performance measuring apparatus of the present invention according to the acceleration sensor performance measuring method of the present invention, centrifugal force is applied to the acceleration sensor as acceleration to be measured to measure the performance of the acceleration sensor (output characteristic). Measurement)
Therefore, the performance can be measured in an acceleration region beyond the gravitational acceleration, and the acceleration can be continuously changed and measured.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a longitudinal sectional view showing a main part of a performance measuring device for an acceleration sensor according to the present invention.

As shown in detail in FIG. 1, in the performance measuring device 9 for an acceleration sensor of this embodiment, the frame 10 includes an upper base 11, a middle base 12 and a lower base 13 which are arranged in the horizontal direction. It is fixedly arranged on a suitable number of columns 14 standing upright in the vertical direction so as to be opposed to each other at various separation distances. Below the desired support 14, a leveling mount 15 is provided which serves as both level adjustment and vibration absorption for the performance measuring device 9 of the acceleration sensor.

The frame 10 formed in this way
Further, a centrifugal force imparting means for imparting a centrifugal force in a direction orthogonal to the direction of gravity to the mounted acceleration sensor 1, an imparting centrifugal force measuring means for determining the centrifugal force imparted to the acceleration sensor, and the acceleration sensor. A sensor output extracting means for extracting an output in response to the measured acceleration is provided.

First, a centrifugal force applying means for applying a centrifugal force to the acceleration sensor 1 in a direction orthogonal to the gravity direction will be described.

At appropriate positions of the middle base 12, main through holes 16 and auxiliary through holes 17 of appropriate sizes penetrating in the vertical direction are formed at desired intervals. Further, the upper base 11 is provided with a through hole 18 of an appropriate size having the same axial center in the vertical direction as the main through hole 16 formed in the middle base 12. And the upper base 1
A rotary shaft 19 is arranged in the vertical direction on the common axis of the through hole 18 provided in the first base hole 16 and the main through hole 16 provided in the middle base 12.

A drive means 20 for the rotating shaft 19 is provided in the sub through hole 17 provided in the middle base 12.
The driving force is transmitted to the drive means 20 and the rotary shaft 19 by belt transmission.

To further explain, the rotary shaft 19 is a stepped shaft having a plurality of different diameter portions whose both ends are smaller in diameter than the central portion, and the upper end is located above the upper base 11, The lower end is located below the middle base 12 and above the lower base 13. Further, the rotary shaft 19 is attached to an appropriate upper support member 21 and lower support member 22, which are fixed to the through hole 18 provided in the upper base 11 and the main through hole 16 provided in the middle base 12, respectively. It is rotatably supported by bearings 23, 23.

As shown in detail in FIG. 2, the upper support member 21 has a substantially cylindrical main body 24 having an outer diameter slightly smaller than the inner diameter of the through hole 18, and a through hole formed in an upper end surface of the main body 24. Large flange portion 25 having a diameter larger than 18 and extending outward in the radial direction, and a small flange having a hole in the axial end portion having a smaller diameter than the through hole 18 and extending in the axial direction in the lower end surface. And part 26. In the upper support member 21, the main body 24 is inserted into the through hole 18 with the small flange portion 26 facing downward, and the large flange portion 2 is inserted.
The lower surface 27 of the upper portion 5 is in contact with the upper surface 28 of the upper base 11, and the large flange portion 25 and the upper base 11 are fixedly attached by an appropriate method (not shown). Further, on the inner peripheral surface of the main body 24, the bearing 23 for supporting the rotating shaft 19 is mounted so as to be in contact with the upper surface 29 of the small flange portion 26 so as to be positioned.

As shown in detail in FIG. 3, the lower support member 22 has a substantially cylindrical main body 30 having an outer diameter slightly smaller than the inner diameter of the main through hole 16, and an appropriate outer peripheral surface of the main body 30. Flange portion 31 that is radially outwardly extended to a position
And a flange portion 32 having a smaller diameter than the through hole and having a hole in the axial center portion extending in the axial direction in one end surface of the main body 30. This lower support member 22
Inserts the main body 30 into the main through hole 16 with the flange portion 32 facing upward, and the upper surface 33 of the collar portion 22 is inserted into the middle base 1.
2 is in contact with the lower surface 34 of the flange 2, and the flange 31 and the middle base 1
2 and 2 are fixedly attached by an appropriate method not shown. Further, on the inner peripheral surface of the main body 30, the bearing 23 for supporting the rotating shaft 19 described above is provided on the lower surface 3 of the flange portion 32.
5 is brought into contact with and positioned so as to be mounted.

Further, as shown in detail in FIGS. 2 and 3,
The bearing 23 mounted on the upper support member 21 is fixed to the rotary shaft 19 by a snap ring 36, and the bearing 23 mounted on the lower support member 22 is fixed to the rotary shaft 19 by a washer 37 and a bearing nut 38. ..

A measuring arm 44 having a substantially rectangular cross section and having a desired length is disposed above the rotary shaft 19 in a horizontal direction orthogonal to the rotary shaft 19 through a supporting member 43 having an appropriate shape. .. Then, at a suitable position on the upper surface 45 of the measuring arm 44, a sample table 46 having a substantially L-shaped cross section on which the acceleration sensor 1 is mounted is fixed with the reference surface 47 as the vertical direction. The measuring arm 44 may be formed in a disc shape and is not particularly limited to this embodiment.

Further, each bearing 2 of the rotating shaft 19 described above.
At a position between 3 and 23, the middle base 12 to the upper base 1
The driven pulley 55 that transmits the driving force toward 1, the flywheel 56 that stabilizes the rotation of the rotating system including the rotating shaft 19, and the input / output means for the external device including the slip ring 39 are appropriate methods. It is fixed by.

Further, the part of the driving means 20 disposed in the sub through hole 17 of the middle base 12 will be further described. As shown in FIG.
An appropriate support member 57 is fixed to the lower surface of 2.
The support member 57 has a substantially cylindrical main body 58 having an outer diameter slightly smaller than the inner diameter of the auxiliary through hole 17, and an outer flange 59 extending radially from the outer periphery of the main body 58 at a substantially intermediate position in the axial direction. And an inner flange 60 having a hole in the axial center portion extending from the inner periphery of the main body 58 in the axial direction. The main body 58 of the support member 57 is loosely fitted in the auxiliary through hole 17, and the upper surface 61 of the outer flange 59 is brought into contact with the lower surface 34 of the middle base 12 to connect the outer flange 59 and the middle base 12. It is fixedly attached by an appropriate method not shown. Further, on the inner peripheral surface 63 of the main body 58, two bearings 23, 23 from both ends are abutted against the end surfaces 64, 64 of the inner flange 60 and positioned and mounted. Further, a shaft 65 having the bearings 23, 23 as a common shaft center is vertically inserted into the bearings 23, 23,
The middle base 12 side is fixed by a retaining ring 36, and the lower base 13 side is fixed by a bearing nut 38 so as to be rotatable.

The upper end of the shaft 65 is located above the middle base 12, and the lower end is located below the middle base 12. A drive pulley 66 is fixed to the upper end of the shaft 12, and a drive motor 67 is connected to the lower end of the shaft as a drive unit 20 via an appropriate joint 51. This drive motor 67 has an appropriate mounting member 68.
Thus, it is attached to the middle base 12 via the support member 57.

A belt 69 is wound around the drive pulley 66 mounted on the shaft 65 and the driven pulley 55 mounted on the rotary shaft 19, and the driving force from the drive motor 67 is applied to the rotary shaft 19. It is possible to transmit.

The transmission means for transmitting the driving force from the drive motor 67 to the rotary shaft 19 is not belt transmission but may be selected from known transmission means and applied, and is not particularly limited to this embodiment. Absent. Further, the drive motor 67
May be directly attached to the middle base 12, and the drive pulley 66 may be directly fixed to the output shaft 70 of the drive motor 67.

Next, the applied centrifugal force measuring means for obtaining the centrifugal force applied to the acceleration sensor 1 will be described.

In this embodiment, the rotation angle of the rotary shaft 19 is measured by the encoder 52, and the acceleration sensor 1
The magnitude of the centrifugal force applied to is calculated.
That is, an appropriate joint 51 is attached to the lower end of the rotary shaft 19.
The encoder 52 is connected via. The encoder 52 is attached to the middle base 12 via the lower support member 22 by an appropriate attachment member 53. Further, the rotation angle of the rotary shaft 19 measured by the encoder 52 is output to an appropriate external device (not shown) to calculate the centrifugal force applied to the acceleration sensor 1, and the acceleration measured by the acceleration sensor 1 It is designed for comparison.

The lower end of the rotary shaft 19 may be formed in an appropriate shape and directly fixed to the input shaft 54 of the encoder 52.

A non-contact type tachometer, stroboscope or the like may be used for measuring the number of rotations or the rotation speed of the rotary shaft 19, and the present invention is not particularly limited to this embodiment.

Next, the sensor output extracting means for extracting the output in response to the acceleration measured by the acceleration sensor 1 will be described.

In this embodiment, the output is formed and the power is supplied. That is, as shown in FIG. 1, a hole 40 is formed in the shaft center portion of the rotating shaft 19 from the upper end to the mounting position of the slip ring 39, and the rotating shaft 1 near the mounting position of the slip ring 39.
The outer peripheral surface of 9 is communicated with a hole 41 bored in the axial direction to form a communication hole.

At the upper end of the rotary shaft 19, there is fixed a control box 48 in which a regulator of a power supply for supplying power to the acceleration sensor 1 and a conversion circuit for the output of the acceleration sensor 1 are built in. A terminal 50 to which the cord 49 of the acceleration sensor 1 is connected is provided on the side surface, and desired wiring is routed from the end surface facing the rotating shaft 19 to the slip ring 39 through the communication hole 42. There is. The control box 48 may be a terminal for routing the wiring without incorporating the regulator of the power source and the conversion circuit of the output of the acceleration sensor 1, and is not particularly limited to this embodiment. Further, the acceleration sensor 1 extracted from the slip ring 39
Is output to an appropriate comparison means (not shown) for comparison with the centrifugal force applied to the acceleration sensor 1.

Next, the operation of this embodiment having the above-mentioned structure will be described with reference to FIG.

First, the performance measuring device 9 of the acceleration sensor having the above-described structure is installed at a desired place. Then, at the time of installation, an appropriate level is placed on the measurement arm 44 of the frame 10, and the leveling mount 15 arranged below the frame 10 is adjusted to perform horizontal alignment, so that the upper surface 45 of the measurement arm 44 is removed. It is made orthogonal to the direction of gravity indicated by arrow C in FIG. Further, the sample table 4 fixed to the horizontal arm 44
The acceleration sensor 1 is mounted on the reference surface 47 of No. 6 such that its measurement axis is orthogonal to the direction of gravity.

As a result, the measuring axis of the acceleration sensor 1 attached to the performance measuring device 9 of the acceleration sensor shown by the arrow B in FIG. 1 is always held in the direction orthogonal to the direction of gravity. Therefore, the gravitational acceleration measured by the acceleration sensor 1 becomes 0 G due to its characteristic (see FIG. 9), and the acceleration sensor 1 measures only the centrifugal force acting in the measurement axis B direction.

Next, by connecting the cord 49 of the acceleration sensor 1 to the terminal 50 provided on the side surface of the control box 48, the electric power supply to the acceleration sensor 1 and the output of the acceleration sensor 1 are performed via the slip ring 39. Then, the data is output to a known appropriate comparison means (not shown).

Next, when the drive motor 67 is operated,
The driving force is transmitted to the rotary shaft 19 by the belt 69, and the rotary shaft 19 starts rotating with the flywheel 56 in a state where the drive force is stored as kinetic energy.
The measurement arm 44 fixed to the upper part of 9 rotates in a horizontal plane orthogonal to the direction of gravity, and the acceleration due to the centrifugal force is applied to the acceleration sensor 1 mounted on the sample table 46 fixed to the measurement arm 44 as shown in FIG. Is given from a direction orthogonal to the direction of gravity indicated by arrow B. Then, as described above, the output from the acceleration sensor 1 is the slip ring 39
Is output to an appropriate comparison means (not shown).

The rotation speed of the rotary shaft 19 is output by the encoder 52 in real time to an appropriate comparison means (not shown). Then, in the comparison means, the rotating shaft 19
The actual acceleration value consisting of the centrifugal force applied to the sensor 1 is obtained from the rotation speed of the acceleration sensor 1, and at the same time, the acceleration value detected by the acceleration sensor 1 is compared to evaluate the performance of the acceleration sensor 1. It

The performance of the acceleration sensor 1 can be measured by changing the rotational speed of the drive motor 67 and continuously increasing the applied centrifugal force from zero. The performance can also be measured by increasing the rotation speed and applying a centrifugal force of 1 G or more.

Therefore, according to the present embodiment, the acceleration sensor 1 is operated while continuously changing the acceleration of the centrifugal force.
Since the output of the acceleration sensor 1 can be continuously detected, the performance of output linearity of the acceleration sensor 1 can be easily measured, and the acceleration sensor in the acceleration region exceeding the gravitational acceleration can be easily measured. 1 performance measurement is possible. Further, since the acceleration measured by the acceleration sensor 1 is a centrifugal force that is always applied in the same direction as the measurement axis B, various influences caused by changing the inclination angle of the acceleration sensor 1 as in the conventional art are generated. Can be reliably prevented.

Further, by inverting the acceleration sensor 1 in the horizontal direction and attaching it to the sample stand 46 in the opposite direction, the acceleration in the negative direction can be measured.

The present invention is not limited to the above-described embodiment, and for example, the performance measurement of a plurality of acceleration sensors 1 can be performed by disposing a plurality of sample stands 46 on the upper surface 45 of the measurement arm 44. Various changes can be made as necessary, such as simultaneous execution.

[0051]

As described above, according to the method and apparatus for measuring the performance of the acceleration sensor of the present invention, the centrifugal force as the acceleration applied to the acceleration sensor during the performance measurement is maintained in the same direction as the measuring direction. It is possible to reliably prevent various effects that occur by changing the inclination angle of the acceleration sensor, and by applying centrifugal force, continuously measuring performance in the acceleration region exceeding the gravitational acceleration. In addition, it is possible to obtain the extremely excellent effect that the performance measurement of the output linearity can be performed easily and efficiently.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an entire performance measuring device for an acceleration sensor according to the present invention.

FIG. 2 is an enlarged view of the vicinity of the through hole in FIG.

FIG. 3 is an enlarged view of the vicinity of the main through hole in FIG.

FIG. 4 is an enlarged view of the vicinity of the auxiliary through hole in FIG.

FIG. 5 is a diagram showing a main part of an acceleration sensor.

FIG. 6 is a front view showing the entire performance measuring device of a conventional acceleration sensor.

FIG. 7 is an explanatory diagram illustrating acceleration measurement by a conventional performance measuring device for an acceleration sensor.

FIG. 8 is a view similar to FIG.

9 is a view similar to FIG. 7.

[Explanation of symbols]

 1 Accelerometer 9 Performance Measuring Device for Accelerometer 10 Frame 15 Leveling Mount 16 Main Through Hole 17 Sub Through Hole 18 Through Hole 19 Rotating Shaft 20 Drive Means 21 Upper Support Member 22 Lower Support Member 39 Slip Ring 42 Communication Hole 43 Support Member 44 Measuring arm 46 Sample stand 47 Reference plane 48 Control box 52 Encoder 55 Driven pulley 56 Flywheel 57 Support member 66 Drive pulley 67 Drive motor 69 Belt

Claims (2)

[Claims] 1. An acceleration sensor is provided with a centrifugal force in a direction orthogonal to the direction of gravity as an acceleration to be measured, and the applied centrifugal force is compared with the acceleration measured by the acceleration sensor to perform performance measurement. A method for measuring the performance of an acceleration sensor. 2. A centrifugal force applying means for applying a centrifugal force to the mounted acceleration sensor in a direction orthogonal to the direction of gravity,
A performance measuring device for an acceleration sensor, comprising: an applied centrifugal force measuring means for obtaining a centrifugal force applied to the acceleration sensor; and a sensor output extracting means for extracting an output in response to the acceleration measured by the acceleration sensor.