JP4411034B2 - Apparatus and method for calibration and evaluation of accelerometer by impact acceleration generation using multiple projectiles - Google Patents

Description

  The present invention relates to an apparatus and method for calibrating and evaluating an acceleration sensor based on the generation of impact acceleration using multiple flying objects, and the field of the technology to which the present invention belongs is a field in which measurement of motion is indispensable, for example, vehicle collision safety. This is a field for measuring acceleration in vehicle suspensions, robots, transportation equipment, nuclear power generation related equipment, ships, aerospace equipment, human body vibrations.

  Conventionally, a method of installing an acceleration sensor on a one-dimensional shaking table and measuring the motion of the shaking table with a laser interferometer has been regarded as the most reliable method and has been used as a primary standard. As a method of generating impact acceleration, a metal projectile is launched from a simple launch tube and collided with the rod end surface, and the elastic wave pulse generated inside the rod is reflected by the other rod end surface to which the acceleration sensor is attached. A method for evaluating the frequency characteristics of the acceleration sensor based on the impact acceleration generated at the end face of the sensor has already been put into practical use (see, for example, Patent Document 1). Further, as described in Non-Patent Document 1, a metal sphere is brought into contact with and fixed to one end face of a round bar, and another metal sphere is caused to fly and collide with the metal sphere. When the elastic wave pulse generated inside is reflected by the other end face of the rod to which the acceleration sensor is attached, a method for evaluating the frequency characteristic of the acceleration sensor by the impact acceleration generated at the end face has been internationally standardized.

  In addition, as an accelerometer (acceleration sensor), an AC accelerometer (acceleration sensor) and a DC accelerometer (acceleration sensor) are known. In the frequency characteristics, an input acceleration in an AC frequency band not including a DC component is used. An accelerometer (acceleration sensor) that responds is called an AC accelerometer (AC acceleration sensor), and an accelerometer (acceleration sensor) that responds to input acceleration in the AC frequency band including the DC component in frequency characteristics. DC accelerometer (DC acceleration sensor).

Japanese Patent Publication No. 6-52270 ISO / FDIS 16063-13, Part 13: Primary shock calibration using laser interferometry

  Since these methods cannot control the duration of impact acceleration, there is a drawback that the duration of impact acceleration to be generated is too short, that is, the frequency band is too wide. Resonance is excited when an impact acceleration in a frequency band that is too wide is input to the acceleration sensor, but normally the acceleration sensor is used in a frequency band where resonance is not excited, so the correct frequency response may not be obtained. At the same time, peak sensitivity cannot be measured. It is impossible in principle to apply a filter.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an acceleration sensor calibration evaluation apparatus and method using an impact acceleration generation using a multiple flying object that solves the above problems.

  A more specific object of the present invention is to apply an impact to one end surface of a round bar, and to generate the elastic wave pulse generated inside the round bar by the impact, and to reflect the reflection at the other end surface of the round bar. It is an object of the present invention to provide a calibration evaluation apparatus and method for an acceleration sensor by generating impact acceleration using a multiple projectile capable of freely controlling the waveform and frequency band of impact acceleration.

According to one aspect of the present invention, a flying object accommodated in a launch tube is caused to fly from the other end of the launch tube by the pressure of high-pressure gas injected into the launch tube from one end of the launch tube. collide with one end surface of the rod, in the calibration method for evaluating the acceleration sensor for calibrating the acceleration sensor attached to the other end face of the rod, the projectile from two or more flying bodies independent of each other The pressure position of the high-pressure gas is directly supported by the pressure receiving body movable in the launch tube so as to be separable, and the tip positions in the flight direction are different from each other in the state of being supported by the pressure receiving body. of the projectile, it is driven to fly simultaneously by said high pressure gas, wherein the first step to one end face sequentially collides with a small time difference of the round bar, one of the round bar by the two or more projectile The impact applied to the surface, and the acceleration sensor movement of the end surface caused by reflection at the other end face of the rod acoustic wave pulse generated within the rod, attached to the end face of the other, calibration And a third step of calibrating the acceleration sensor based on an output signal from the acceleration sensor and a result obtained by the calibration input acceleration measurement device . It is characterized by that.

According to another aspect of the present invention, a projectile housed in a launch tube is caused to fly from the other end of the launch tube by the pressure of high-pressure gas injected from the one end of the launch tube into the launch tube. In an acceleration sensor calibration evaluation apparatus for calibrating an acceleration sensor that collides with one end face of a round bar and is attached to the other end face of the round bar, the flying body includes two or more independent flying bodies. And is supported by the pressure receiving body that can directly receive the pressure of the high-pressure gas and is movable in the launch tube, and the tip positions in the flight direction are different from each other in the state of being supported by the pressure receiving body. Means for simultaneously driving and flying the above flying objects with the high-pressure gas and sequentially colliding with one end face of the round bar with a minute time difference, and controlling the injection of the high-pressure gas into the launch tube. Means for a calibration input acceleration measuring device which measures the movement of the other end surface of the rod, the one impact applied to the end face of the rod by the two or more flying bodies, the inside of the rod The movement of the end face generated by reflection of the elastic wave pulse generated at the other end face of the round bar is measured by an acceleration sensor attached to the other end face of the round bar and the calibration input acceleration measuring device. resulting Te, based on the measurement result output signal and the calibration input acceleration measuring device from the acceleration sensor, characterized by comprising a calibration means for calibrating the acceleration sensor.

  Further, the two or more flying bodies are a first flying body located on a central axis of the pressure receiving body, and are located outside the first flying body and coaxially with the first flying body. And at least one second flying object.

  Furthermore, any one of the first and second flying bodies may be integral with the pressure receiving body.

  Furthermore, at least one of the two or more flying objects may have a material of the collision end portion different from that of the other portions.

Furthermore, it is possible to be at least one material of said two or more projectile is different from the material of the other projectile.

Furthermore, it is possible to the contacting the metal ball fixed to one end face of the round bar, and Rukoto to collide with the two or more projectile into the metal ball.

  Furthermore, the calibration input acceleration measuring device may be at least one strain gauge attached to a side surface of the round bar.

Furthermore, the strain plurality pasted gauge in the axial direction of the rod, prior SL-axis direction of pasting the phase of each strain gauge output waveforms different in each position, the elastic at a point in the axial direction of the rod It is possible to perform signal processing that converts the distortion into wave pulses and adds the respective strain gauge outputs after the conversion to reduce noise.

Furthermore, with one point in the axial direction of the round bar as a representative position, the distortion of the elastic wave pulse incident on the end face of the round bar to which the acceleration sensor necessary for obtaining the input acceleration applied to the acceleration sensor is obtained , It can be determined from the distortion of the elastic wave pulse at the representative position .

Further, the output signal of the strain gauge is divided by a correction function that corrects the output signal of the strain gauge obtained based on the measurement result of the laser interferometer that directly measures the movement of the other end face of the round bar to a true strain. Then, it is possible to obtain the distortion of the elastic wave pulse incident on the end face of the round bar to which the acceleration sensor is attached, which is necessary for obtaining the input acceleration applied to the acceleration sensor.

Further, when obtaining a transient strain signal of an elastic wave pulse incident on the other end face of the round bar from the strain gauge output signal, the round bar separated from the end face caused by an impact applied to one end face of the round bar. it can be and Turkey using at least first-order terms of analytical solutions when deployed strain of the elastic wave pulses with a stick of the cross-section in series.

  Furthermore, the calibration input acceleration measuring device may be a laser interferometer that directly measures the movement of the other end face of the round bar.

  Further, when the acceleration sensor is calibrated, the peak sensitivity value of the sensor obtained as a function of the frequency band of the shock acceleration signal is increased by controlling the frequency bandwidth of the shock acceleration signal applied to the sensor. Then, the signal frequency bandwidth and peak sensitivity of the input impact acceleration that can actually be used for acceleration measurement can be obtained.

  The present invention relates to a dynamic displacement in a direction perpendicular to the end face generated in the process in which an elastic wave generated by applying an impact to the end face of a round bar propagates inside the bar to reach the other end face and reflects. Speed and acceleration are used as input signals to the acceleration sensor attached to the end face, and these input signals as a function of time are measured by the calibration input acceleration measurement device, and the output signal of the acceleration sensor and the calibration input acceleration measurement device By performing signal processing operations such as Fourier transform, Laplace transform, and filter operation on the output signal, the gain of the acceleration sensor related to each function of the dynamic displacement detection function, speed detection function, and acceleration detection function of the acceleration sensor The frequency characteristics, phase-frequency characteristics, and peak sensitivity can be measured by controlling the frequency band of the input impact acceleration.

1) It is possible to control the frequency band of impact acceleration when generating impact acceleration. Compared to a single launch of a flying object, particularly a single launch of a flying object made of only a metal such as aluminum, the duration of the elastic wave pulse can be increased by 10 times or more. This increases the usefulness of impact acceleration as a measurement standard. It is possible to expand an area where the acceleration sensor calibratable area by the shaking table and the acceleration sensor calibratable area by the impact acceleration overlap.
2) In the evaluation of the acceleration sensor, the frequency characteristic may vary depending on the structure of the acceleration sensor depending on how much the frequency component of the incident impact acceleration includes the component that excites the resonance frequency. The dependence of frequency characteristics on the input acceleration frequency band can be clarified.
3) Since the metal round bar to which the acceleration sensor is attached is an axis object, the generated acceleration has extremely high linearity. According to the present invention, it is possible to calibrate an acceleration sensor that has less influence of parasitic lateral vibration than the acceleration sensor using the vibration table, and therefore has less uncertainty than the calibration of the acceleration sensor using the vibration table. (The parasitic transverse vibration of the one-dimensional shaking table itself has frequency-dependent characteristics, but is usually ignored).
4) Impact acceleration waveform and distortion waveform data obtained by launching individual flying objects independently, and impact acceleration waveform and distortion waveform data obtained by controlling the timing of continuous collision of multiple flying objects Is made into a database using the structure of the flying object, the shape of the flying object, the firing condition of the flying object, and the collision timing between the flying objects as parameters, so that the impact acceleration can be generated flexibly.
5) In an acceleration sensor for impact acceleration measurement, the frequency characteristics of the acceleration sensor are unclear in relation to the resonance frequency, and the measurable frequency band and upper limit frequency are unclear. Since the input acceleration frequency band dependence characteristic can be clarified, the reliability of the peak value measurement of the impact acceleration is improved.
6) By attaching a large number of strain gauges to the side surface of the round bar, noise can be reduced in the measurement of the peak value of low impact acceleration.
7) Impact testing in a frequency band with a wide range of industrial applications is possible.
8) The usable frequency band of the acceleration sensor is accurately defined.

(Explanation of the entire calibration device)
(A) of FIG. 1 shows the structure of the acceleration sensor calibration apparatus by the impact acceleration using a multiple flying body. Reference numeral 1 denotes a metal rod that is sufficiently long compared to its diameter, and is horizontally supported by bearings placed in two grooves (not shown) at a plurality of locations, and is not constrained in the axial direction. Reference numeral 2 denotes a launch tube as a means for applying an impact to one end face of the round bar 1 and simultaneously drives three flying bodies 3A, 3B, 3C (see FIG. 1B) simultaneously with high-pressure air. It is positioned and fixed by appropriate fixing means so as to fly and collide sequentially with one end face of the round bar 1 with a minute time difference. The structure of the flying object will be described later.

Reference numeral 4 denotes an acceleration sensor attached to the other end face of the round bar 1, and reference numeral 5 denotes a plurality of strain gauges as a calibration input acceleration measuring device for measuring the movement of the other end face of the round bar 1. Then, a plurality of pieces are attached in the circumferential direction and the axial direction on the side surface of the round bar 1 (the surface excluding both end faces in the axial direction of the round bar 1).
6 is a laser beam irradiated to the other end surface of the round bar 1, and is emitted from a laser interferometer (not shown). The detection output signal of the acceleration sensor 4, the detection output signal of the strain gauge 5, and the detection output signal of the laser interferometer are supplied to an arithmetic device (usually constituted by a computer), and will be described later by the arithmetic device. Various calculations for calibration of the acceleration sensor are performed.

As shown in FIG. 2, the three flying bodies 3A, 3B, 3C form a triple structure, of which the innermost flying body 3A has an axial shape, and its base end is the launch tube 2 It is screwed and fixed to the center of a flange 3D as a pressure receiving body provided so as to be airtightly movable in the axial direction. The intermediate tubular flying body 3B is slidably disposed on the outside of the flying body 3A, and further, the tubular flying body 3C is disposed on the outside of the flying body 3B so as to be slidable with respect to each other. In this state, the flying object 3B has a length that does not protrude further downstream than the flying object 3A in the flying direction. body 3C, from the projectile 3B is the total length of the flying direction of which has (projectile 3A and the flange 3D has a length which does not protrude on the downstream side of the flight direction and L _1, 2 single projectile 3B, L ₁ > L ₂ > L ₃ ) where L ₂ and L ₃ are the lengths in the flight direction of 3C, respectively. That is, the three flying bodies 3A, 3B, and 3C are supported by the flange 3D and have different tip positions in the flying direction.

  With the flange 3D not projecting from the opening end of the launch tube 2, the tip of the innermost projecting body 3A touches one end surface of the round bar 1, and the center of the flange 3D, that is, the projecting object. The distance and the positional relationship between the launch tube 2 and one end face of the round bar 1 are adjusted so that the axis of 3A coincides with the axis of the round bar 1.

  The end of the firing tube 2 on the closing side is connected to a high-pressure air source 8 via an opening / closing valve 7, and the opening / closing of the opening / closing valve 7 is controlled by a valve opening / closing controller 9. When the flange 3D supporting the two flying bodies 3B, 3C is on the closed end side of the launch tube 2 and the opening / closing valve 7 is opened from the closed state by the valve opening / closing control device 9, high-pressure air passes through the opening / closing valve 7. The flange 3D is instantaneously supplied into the launch tube 2, and the flange 3D is driven by the supplied high-pressure air. As a result, the flange 3D moves at high speed toward one end face of the round bar 1, and the two projectiles are moved by the flange 3D. 3B and 3C are simultaneously driven and flew (the flying object 3A integrated with the flange 3D also flies at the same time). First, the innermost flying object 3A first collides with one end surface of the round bar 1, and the flange The two flying bodies 3B and 3C supported by 3D are separated from the flange 3D, the intermediate flying body 3B next collides with one end face of the round bar 1, and the outermost flying body 3C is the round bar 1 Collides with one end face last

The three flying bodies 3A, 3B, 3C can also be configured as shown in FIG. That is, the center portion of the flange 3D is protruded from the outer portion, the innermost flying body 3A is screwed and fixed to the center of the protruding portion, and the intermediate tubular flying body 3B is supported by the protruding portion. Are arranged slidably on the outside of the flying body 3A, and further, the tubular flying body 3C is slidably arranged on the outside of the flying body 3B so as to be supported by the outer portion of the protruding portion of the flange 3D. and, the two projectile 3B, 3C and is obtained by so as to detachably supporting the flange 3D, and in its supported state, the sum of the flying object 3A and the flange 3D flight direction of the length of the L _1, When the lengths of the two flying bodies 3B and 3C in the flying direction are L ₂ and L ₃ , respectively, L ₁ > L ₃ > L ₂ is satisfied. In such a configuration, it is not necessary to make the length of the outermost flying object 3C shorter than the length of the intermediate flying object 3B. As described above, the frequency bandwidth of the impact acceleration generated on the end face of the round bar can be more easily controlled by changing the relationship between the lengths of the three flying objects as compared with that of FIG. 2 and 3, the innermost flying body 3A can be separated from the flange 3D in the same manner as the other two flying bodies, without the structure of being screwed and fixed to the flange 3D. It may be. In the configuration of FIG. 3 as well, the three flying bodies 3A, 3B, and 3C are supported by the flange 3D, and the tip positions in the flying direction are different from each other.

Further, the three flying bodies 3A, 3B, 3C can be configured as shown in FIG. In this example, the outermost flying body 3C is screwed and fixed to the flange 3D, and an intermediate flying body 3B is slidably disposed inside the outermost flying body 3C, and the inner side of the intermediate flying body 3B. The innermost flying body 3A is slidably arranged on the other side, and these two flying bodies 3A and 3B are detachably supported by the flange 3D. In this supported state, the flying body 3C and the flange are supported. the sum of the flying direction of the length of the 3D and _{L 1,} 2 single projectile 3A, the flying direction of 3B length respectively When _{L 3, L 2,} is obtained by the _{L 1>} L _2> L ₃ . Also in this configuration, the three flying bodies 3A, 3B, and 3C are different from each other in the tip position in the flying direction while being supported by the flange 3D. According to this configuration, the three flying bodies 3A, 3B, 3C are simultaneously driven to fly and sequentially collide with one end face of the round bar 1 in the order of the flying body 3C, the flying body 3B, and the flying body 3A.

FIG. 5 shows an example of four flying bodies 3A, 3B, 3C, 3E. In this example, an intermediate flying body 3B is slidably disposed inside the outermost flying body 3C, and another intermediate flying body 3E is slidably disposed inside the intermediate flying body 3B. Then, the innermost flying body 3A is slidably disposed inside the other intermediate flying body 3E, and these four flying bodies 3A, 3B, 3C, 3E are detachably supported by the flange 3D. If the lengths of the four flying bodies 3A, 3B, 3C, and 3E in the flying direction are L ₄ , L ₁ , L ₂ , and L ₃ in the supporting state, respectively, L ₁ > L ₂ > L ₃ > L ₄ Also in this configuration, the four flying bodies 3A, 3B, 3C, and 3E are supported by the flange 3D, and the tip positions in the flying direction are different from each other. According to this configuration, the four flying bodies 3A, 3B, 3C, and 3E are simultaneously driven to fly, and one of the round bars 1 is in the order of the flying body 3B, the flying body 3C, the flying body 3E, and the flying body 3A. It collides sequentially with the end face.

  Further, the plurality of flying bodies may be a plurality of spheres having different diameters. In this case, an appropriate support structure is provided for the flange 3D (for example, a plurality of pipes having an inner diameter in which the respective spheres are inserted are fixed to the flanges, and the spheres are inserted therein). When inserted into the launch tube 2 and driven with high-pressure air and the flange 3D is stopped at the open end of the launch tube 2, each sphere jumps out of the respective tube and collides with one end face of the round bar 1.

  Reference numeral 10 denotes a laser light source, and laser light emitted from the laser light source is reflected by two mirrors 11 (one mirror is semi-transmissive and transmits a part of the laser light), and the axis of the round bar 1 is reflected. The light passes through the vicinity of one of the end faces orthogonally and enters the two light receiving elements 12. The light reception outputs of the two light receiving elements 12 are input to a counter 13 that measures the speed when the flying object collides with the round bar 1. Immediately before the flying object is driven to fly and collide with one end face of the round bar 1, the tip of the innermost flying object 3A first shields the laser beam on the launch tube 2 side, and then the round bar 1 The side laser beam is shielded. When the laser beam is blocked, the light receiving output of the light receiving element is turned off. Therefore, when the flying object 3A collides, the counter 13 counts the timing between the two light receiving output signals from the two light receiving elements 12 between OFF and OFF, and the flying object collision speed is based on the count result. Can be measured. The same configuration as described above is provided for each of the intermediate flying body 3B and the outermost flying body 3C. That is, the laser beams from the laser light sources other than the laser light source are shielded immediately before the tips of the intermediate projecting body 3B and the outermost projecting body 3C collide with one end surface of the round bar 1. Two laser light sources, two mirrors for each of the two laser light sources, and two light receiving elements (not shown) are provided, and the light reception outputs of the two (four total) light receiving elements are input to the counter 13. Then, the same measurement as described above is performed. The measurement result of the counter 13 is supplied to the above-described arithmetic device and used for the calibration process of the acceleration sensor.

  According to the above configuration, the flying bodies 3 </ b> A, 3 </ b> B, and 3 </ b> C are caused to collide with one end face of the round bar 1 and an impact is applied to generate an elastic wave pulse inside the round bar 1. At that time, by shifting the timing of the collision of each flying object with one end face of the round bar 1, the duration of the elastic wave pulse as a whole can be extended according to the principle of superposition. Details will be described later with reference to FIG.

Timing of the collision of the projectile has a difference in length of the projectile depends on the impact velocity V _1. Assuming that the speed drop due to friction can be ignored, the entire flying object collides with the end face of the round bar at the same collision speed, but the length of the innermost flying object 3A is L _p1 and the length of the intermediate flying object 3B is L _p2 . Then, the time difference of collision becomes (L _p1 -L _p2 ) / V ₁ .

  The elastic wave pulse generated by the collision of the flying object with one end face of the round bar 1 propagates through the inside of the round bar 1 and reaches the other end face of the round bar 1 to be reflected. The impact acceleration in the direction perpendicular to the end face generated in the reflection process becomes an input to the acceleration sensor attached to the end face.

  The impact acceleration generated on the other end face of the round bar 1 is detected by the laser interferometer provided at a position where the other end face can be irradiated with the laser light from the laser interferometer or a plurality of positions on the side face of the round bar 1. This is performed with the strain gauge 5 attached (including the case of one place in the axial direction).

Here, the impact acceleration generated on the other end face of the round bar due to the single collision of each flying object on one end face of the round bar 1 and the three flying bodies 3A, 3B, 3C are rounded at different collision timings. The relationship with the impact acceleration that occurs when the end face of one of the bars is continuously collided will be described with reference to FIG. As shown in FIG. 6, 21 is a waveform of the impact acceleration measured by the strain gauge generated only by the collision of the innermost flying object 3 </ b> A, and 22 is a distortion gauge generated only by the collision of the intermediate flying object 3 </ b> B. The waveform of the measured impact acceleration, 23 is the waveform of the impact acceleration measured by the strain gauge generated only by the collision of the outermost flying object 3C. From these, the impact acceleration generated by the collision of one flying object It can be seen that the duration of is short. 24 three projectile 3A, 3B, and controls the collision timing of 3C (in FIG. 6, the innermost projectile 3B collision from the middle after a time lapse of alpha ₁ of the projectile 3A collide, likewise, alpha ₂ (the outermost flying object 3C collided after the time of α ₁ <α ₂ )), showing the waveform of the impact acceleration measured by the strain gauge as a whole caused by superposition, and the impact acceleration as a whole duration alpha ₃ of, it can be seen that longer than the duration of the individual impact acceleration above. Reference numeral 25 denotes a distortion waveform of the superimposed incident pulse obtained when the three flying bodies 3A, 3B, and 3C collide. Reference numeral 26 denotes a combined strain waveform (not contributing to the generation of impact acceleration) of the elastic wave pulse reflected from the other end face of the round bar 1.

  When measuring the movement of the other end face of the round bar 1 with a laser interferometer, the other end face of the round bar 1 to which the acceleration sensor to be calibrated is attached is directly irradiated with laser. When measuring with a strain gauge, the noise output is suppressed by converting the output results of multiple gauges to the strain gauge value at a representative position that is signal processed, and at the same time the gauge output at that representative position. A correction function obtained in advance by the laser interferometer is applied to the frequency characteristics of the above so as to obtain a result equivalent to the result measured by the laser interferometer.

  The contact surface between the outermost flying object 3C and the launch tube 2 is lubricated. In order to control (for example, narrow) the frequency band of the elastic wave pulse generated inside the rod by the launch of each flying object, a polymer material, plastic, wood, or the like can be attached to the tip of the flying object. Alternatively, a flying body having a structure in which the flying body main body portion has a laminated structure with different materials such as metal, polymer material, plastics, and wood can be used.

  (Contents of arithmetic processing performed in the arithmetic unit)

Actually, since it is impossible to attach a strain gauge to the boundary between the other end face of the round bar 1 and the side face of the round bar 1, L _n (n = n = 1... N) is assumed to be pasted at a position (see FIG. 1) that is separated. Further, the representative position of the gauge was affixed to a plurality of positions in the axial direction of the rod and L _1. In this case, at each L _n (n = 1... N) position, the incident wave and the reflected wave on the end face to which the acceleration sensor is attached must be observed separately.

By calculating the average of output signals using a plurality of strain gauges, it is possible to reduce the influence of noise and measure minute dynamic strain, that is, low peak acceleration.

Since the motion acceleration of the end face is obtained from the equation (11), the frequency response of the acceleration sensor is obtained according to the following equation.

  When a plurality of strain gauges are attached in the circumferential direction of the round bar 1 and more than one strain gauge is attached in the axial direction, when only one strain gauge is attached in the axial direction. (That is, a plurality of strain gauges are attached in the circumferential direction) converts the output from each of a plurality of strain gauge attachment positions in the axial direction into an output at one representative position in the axial direction. No calculation is necessary. The strain gauge output pasted at one position in the axial direction is merely regarded as the gauge output pasted at the representative point position.

The peak sensitivity of the acceleration sensor is obtained by considering the input signal to the acceleration sensor and the output signal from the acceleration sensor obtained as described above in the time domain. Since there are two types of output signals of the acceleration sensor only on the + side or − side and those on both sides of ±, if the peak sensitivity on the + side is defined as PS ⁺ and the peak sensitivity on the − side is defined as PS ⁻ , (16 ) (17) is obtained.

Here, all peak sensitivities PS ⁺ and PS ⁻ must not be measured in a state where the acceleration sensor internal seismometer system is in resonance. Peak sensitivity increases when resonance occurs. Accordingly, when the peak sensitivity is expressed as a function of the frequency band of the impact acceleration applied to the acceleration sensor as shown in FIG. 7, the peak sensitivity value starts to increase (peak sensitivity: PS ₅ , frequency: f ₅ ). Thus, the usable frequency band (DC to f ₄ ) and the peak sensitivity (PS ₄ ) can be obtained. Control of the frequency band of the impact acceleration applied to the acceleration sensor can be performed by using two or more flying objects as described in detail so far.

  Although the above description has been made with respect to the AC acceleration sensor, the present invention can be similarly applied to a DC acceleration sensor. The difference in the configuration of the acceleration sensor calibration device is that the round bar to which the AC acceleration sensor is attached is supported horizontally, whereas the round bar to which the DC acceleration sensor is attached has its axial direction in the gravitational acceleration direction ( (The vertical direction) is releasably gripped by appropriate gripping means, and when released, the axis direction falls in a state where it matches the gravitational acceleration direction (vertical direction). . The multiple projectile body collides with the lower end surface of the round bar from below. The DC acceleration sensor is attached to the upper end surface of the round bar. And when carrying out a measurement by making the multiple projectile collide against the DC acceleration sensor, the gripping means is released immediately before the multiple projectile is fired. That is, by opening, the round bar floats in the air. In this state, the multiple projectiles collide, and the elastic wave pulse reaches the upper end surface of the round bar and is reflected and detected by the DC acceleration sensor. Then, if necessary, grip the round bar that is still falling. Since it takes a very short time within 1 second from the collision of the multiple projectiles until the output is obtained from the DC acceleration sensor and the strain gauge, the falling distance of the round bar is also short. The operation timing of the valve opening / closing control device and the gripping means can be controlled by, for example, an arithmetic device.

(A) is a figure which shows the structure of the acceleration sensor calibration apparatus by the impact acceleration using the multiple flying body in embodiment of this invention, (b) shows the structure of three flying bodies (one part shows a cross section) ). It is a figure which shows an example of the structure of a multiple flying body. It is a figure which shows another example of the structure of a multiple flying body. It is a figure which shows another example of the structure of a multiple flying body. It is a figure which shows another example of the structure of a multiple flying body. The impact acceleration generated on the other end face of the round bar due to the single collision of each flying object on one end face of the round bar 1 and the three flying bodies 3A, 3B, 3C are shifted by the collision timing and one of the round bars It is a figure which shows the relationship with the impact acceleration which generate | occur | produces when it is made to collide with the end surface of this. It is a figure which shows the relationship between the peak sensitivity of an acceleration sensor, and the frequency band of the impact acceleration applied to an acceleration sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal round bar 2 Launch tube 3A, 3B, 3C Flying object 3D Flange 4 Acceleration sensor 5 Strain gauge 6 Laser beam 7 Valve 8 High pressure air source 9 Valve opening / closing control device 10 Laser light source 11 Mirror 12 Light receiving element 13 Counter

Claims (26)

A projectile housed in the launch tube is caused to fly from the other end of the launch tube by the pressure of the high-pressure gas injected into the launch tube from one end of the launch tube, and collides with one end surface of the round bar In the calibration evaluation method of the acceleration sensor for calibrating the acceleration sensor attached to the other end face of the round bar,
The flying body is composed of two or more flying bodies that are independent from each other, and is supported in a separable manner by a pressure receiving body that can directly receive the pressure of the high-pressure gas and can move in the launch tube. tip position of the flying direction are different from each other, the two or more flying object, said driven to fly simultaneously by high-pressure gas, a first step of sequentially collide with a small time difference on one end face of said rod,
Wherein the two or more impact applied to one end face of the rod by flying object, movement of the end surface caused by reflection at the other end face of the rod acoustic wave pulse generated within rod A second step of measuring by an acceleration sensor attached to the other end surface and a calibration input acceleration measuring device;
A third step of calibrating the acceleration sensor based on an output signal from the acceleration sensor and a result obtained by the calibration input acceleration measuring device ;
Calibration method for evaluating the acceleration sensor by impact acceleration generated using multiple projectile, characterized in that it comprises a. In claim 1 ,
The two or more flying bodies, at least located in the first projectile and, said first an outer projectile the first projectile coaxially located on the center axis of the pressure receiving body A method for evaluating the calibration of an acceleration sensor by generating impact acceleration using a multiple projectile, comprising: a second projectile. In claim 2 ,
One of said 1st and 2nd flying bodies is integral with the said pressure receiving body, The calibration evaluation method of the acceleration sensor by the impact acceleration generation | occurrence | production using the multiple flying body characterized by the above-mentioned. In claim 1 , 2 or 3 ,
At least one of the two or more projectiles is characterized in that the material of the collision end portion is different from the material of the other portions, and the calibration evaluation of the acceleration sensor by the generation of the impact acceleration using the multiple projectile Method. In any one of Claims 1 thru | or 4 ,
Calibration method for evaluating the acceleration sensor that caused by the impact acceleration generated using multiple projectile, characterized in that at least one of the material is different from the material of the other projectile of said two or more projectile. In any one of Claims 1 thru | or 5 ,
Wherein one end face of the round bar is brought into contact with a metal ball fixed, the acceleration sensor due to the impact acceleration generated using multiple projectile, characterized in Rukoto to collide with the two or more projectile to the metal balls Calibration evaluation method. In any one of Claims 1 thru | or 6 .
The calibration input acceleration measuring apparatus is at least one strain gauge affixed to the side surface of the round bar, and the acceleration sensor calibration evaluation method by the generation of impact acceleration using multiple flying objects. In claim 7,
Affixing a plurality of strain gauges in the axial direction of the round bar,
The distortion of the elastic wave pulse at the cross section of the round bar away from the end face caused by the impact applied to one end face of the round bar is expressed as the distance z from the one end face of the round bar and the time from the start of the shock. Let t be a variable,

The phase of said axial stuck varies from position each strain gage output of the waveform distortion of the elastic wave pulse in the axial direction of a point L ₁ of the rod

A calibration evaluation method for an acceleration sensor by generating impact acceleration using a multiple flying object, wherein signal processing is performed to reduce noise by adding the output of each strain gauge after the conversion . In claim 8 ,
One point in the axial direction of the round bar is a representative position, and the distortion of the elastic wave pulse incident on the end face of the round bar to which the acceleration sensor necessary for obtaining the input acceleration applied to the acceleration sensor is obtained is represented by A method for evaluating and calibrating an acceleration sensor by generating an impact acceleration using a multi-flying object, characterized in that it is obtained from distortion of an elastic wave pulse at a position . In claim 8 ,
A correction function for correcting the output signal of the strain gauge based on the measurement result of the laser interferometer that directly measures the movement of the other end face of the round bar to the true strain.

By using the multiple projectile, the strain of the elastic wave pulse incident on the end surface of the round bar to which the acceleration sensor is attached, which is necessary for obtaining the input acceleration applied to the acceleration sensor, is obtained. Calibration evaluation method for accelerometer by generating impact acceleration. In claim 8 or 9 ,
When obtaining a transient strain signal of an elastic wave pulse incident on the other end face of the round bar from the strain gauge output signal, the round bar separated from the end face caused by an impact applied to one end face of the round bar. at least one primary calibration method for evaluating the acceleration sensor by impact acceleration generated using multiple projectile characterized and Turkey using the section analytic solution when deployed in series strain of the elastic wave pulse in a cross section. In any one of Claims 1 thru | or 6 .
The calibration input acceleration measuring device is a laser interferometer that directly measures the movement of the other end face of the round bar, and a method for evaluating and calibrating an acceleration sensor by generating impact acceleration using a multiple flying object. In any one of Claims 1 to 12 ,
When calibrating the acceleration sensor, the peak sensitivity value of the sensor obtained as a function of the frequency band of the impact acceleration signal is increased by controlling the frequency bandwidth of the impact acceleration signal applied to the sensor. A method for evaluating and calibrating an acceleration sensor by generating impact acceleration using a multiple flying object, characterized in that a signal frequency bandwidth and peak sensitivity of an input impact acceleration that can actually be used for acceleration measurement are obtained. A projectile housed in the launch tube is caused to fly from the other end of the launch tube by the pressure of the high-pressure gas injected into the launch tube from one end of the launch tube, and collides with one end surface of the round bar In the acceleration sensor calibration evaluation apparatus for calibrating the acceleration sensor attached to the other end face of the round bar,
The flying body is composed of two or more flying bodies that are independent from each other, and is supported in a separable manner by a pressure receiving body that can directly receive the pressure of the high-pressure gas and move within the launch tube, and is supported by the pressure receiving body. are different tip position of the flying direction to each other, said two or more flying bodies, the high-pressure gas by drives fly at the same time, a means for one end face of the with a small time difference to sequentially collide the rod and means that controls the injection of the high-pressure gas into the firing tube,
An input acceleration measuring device for calibration for measuring the movement of the other end face of the round bar;
Wherein the two or more impact applied to one end face of the rod by flying object, movement of the end surface caused by reflection at the other end face of the rod acoustic wave pulse generated within rod Based on an output signal from the acceleration sensor and a measurement result of the calibration input acceleration measuring device obtained by measuring with an acceleration sensor attached to the other end surface of the round bar and the calibration input acceleration measuring device. Te, calibration evaluation apparatus of the acceleration sensor by impact acceleration generated using multiple projectile, characterized in that example Bei and calibration means for calibrating the acceleration sensor. In claim 14 ,
The two or more flying bodies, at least located in the first projectile and, said first an outer projectile the first projectile coaxially located on the center axis of the pressure receiving body A calibration evaluation apparatus for an acceleration sensor by generating an impact acceleration using a multiple flying object, comprising: a second flying object. In claim 15 ,
One of the first and second flying bodies is integrated with the pressure receiving body, and the apparatus for evaluating and evaluating the acceleration sensor by the generation of impact acceleration using a multiple flying body. In claim 14, 15 or 16 ,
At least one of the two or more projectiles is characterized in that the material of the collision end portion is different from the material of the other portions, and the calibration evaluation of the acceleration sensor by the generation of the impact acceleration using the multiple projectile apparatus. In any of claims 14 to 17 ,
At least one material calibration evaluation apparatus of the acceleration sensor by impact acceleration generated using multiple projectile, characterized in that is different from the material of the other projectile of said two or more projectile. In any of claims 14 to 18 ,
By the contacting the one end face of the rod further comprising a fixed metal spheres, impact acceleration generated using multiple projectile, characterized in Rukoto to collide with the two or more projectile to the metal balls Calibration evaluation equipment for acceleration sensors. In any of claims 14 to 19 ,
The calibration input acceleration measuring apparatus for calibration is an at least one strain gauge affixed to the side surface of the round bar, and is a calibration evaluation apparatus for an acceleration sensor by generating impact acceleration using a multiple flying object. In claim 20 ,
Affixing a plurality of strain gauges in the axial direction of the round bar, the calibration means,
The distortion of the elastic wave pulse at the cross section of the round bar away from the end face caused by the impact applied to one end face of the round bar is expressed as the distance z from the one end face of the round bar and the time from the start of the shock. Let t be a variable,

The phase of said axial stuck varies from position each strain gage output of the waveform distortion of the elastic wave pulse in the axial direction of a point L ₁ of the rod

An apparatus for evaluating and calibrating an acceleration sensor by generating an impact acceleration using a multiple flying object, wherein signal processing for reducing noise is performed by adding the output of each strain gauge after the conversion . In claim 21 ,
The calibration means uses one point in the axial direction of the round bar as a representative position, and the elastic wave pulse incident on the end face of the round bar to which the acceleration sensor necessary for obtaining the input acceleration applied to the acceleration sensor is attached. An apparatus for evaluating and calibrating an acceleration sensor by generating impact acceleration using a multiple flying object , wherein the distortion is obtained from the distortion of an elastic wave pulse at the representative position . In claim 21 ,
The calibration means corrects the output signal of the strain gauge based on the measurement result of the laser interferometer that directly measures the movement of the other end face of the round bar to correct the true strain. function

By using the multiple projectile, the strain of the elastic wave pulse incident on the end surface of the round bar to which the acceleration sensor is attached, which is necessary for obtaining the input acceleration applied to the acceleration sensor, is obtained. Calibration evaluation device for acceleration sensors by generating impact acceleration. In claim 21 or 22 ,
When the calibration means obtains a transient strain signal of an elastic wave pulse incident on the other end face of the round bar from the strain gauge output signal, the calibration means separates from the end face caused by an impact applied to one end face of the round bar. All accelerometer by multiple projectile impact acceleration generation using, characterized in the Turkey using at least first-order terms of analytical solutions when deployed in series strain of the elastic wave pulse in a cross section of the rod Calibration evaluation device. Any one of claims 14 to 24 .
The calibration input acceleration measuring device for calibration is a laser interferometer that directly measures the movement of the other end face of the round bar, and is a calibration evaluation device for an acceleration sensor using impact acceleration generation using a multi-flying object. In any one of Claims 14 thru | or 25 .
The calibration means controls the frequency bandwidth of the impact acceleration signal applied to the sensor when calibrating the acceleration sensor, thereby obtaining the peak sensitivity of the sensor obtained as a function of the frequency bandwidth of the impact acceleration signal. Acceleration sensor calibration and evaluation device using impact acceleration generation using multiple projectiles, characterized by obtaining signal frequency bandwidth and peak sensitivity of input impact acceleration that can be actually used for acceleration measurement after increasing the value .

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