JP3503087B2 - Vibration reproduction device using sound waves - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration reproducing apparatus which corrects a preset vibration waveform and reproduces the corrected vibration waveform by sound waves.

[0002]

2. Description of the Related Art Conventionally, a vibration generator for generating vibration is
A table surface on which the vibrated body is placed has a side length of 500 (millimeters) to 2000 (millimeters) and a total weight of 3 tons to 5 tons. A hydraulic system was used. Also in the vibration tester,
An apparatus in which the response waveform of a vibration system is corrected so that it matches a preset target waveform is disclosed in Japanese Patent Laid-Open No. 60-254.
No. 211 proposed.

According to this, in order to obtain highly reliable data for guaranteeing seismic resistance in a vibration test of a structure or the like, a vibration waveform with a small target waveform gain is used as a vibration table for a preceding test. In addition, the response waveform obtained from this is sampled and the transfer function is calculated from both waveforms, while the target waveform is Fourier transformed to obtain the ratio of the real part and the imaginary part of each frequency component, and this ratio and the transfer function Is used to correct the waveform applied to the vibration table so that the response waveform of the vibration table matches the target waveform.

As a vibrating device for a material, a device for generating a sound wave to vibrate the material is disclosed in Japanese Patent Laid-Open No. 13455/1993.
No. 9 proposed.

According to this method, in order to obtain the mechanical constant of the material, the material is placed on one surface of the sound insulating plate having a predetermined hole through the non-conductive member, and the other surface of the plate is mounted. A sound wave generator that generates a sound wave is attached to the material, and the sound wave generated from the sound wave generator passes through the hole of the plate and vibrates the material.

[0006]

However, since the conventional vibration generator is large and expensive, it is not suitable for research that does not require a large-scale device.

In particular, the one disclosed in Japanese Patent Laid-Open No. 60-254211, which is intended for the vibration test of structures and the like, requires a large scale and a large testing machine. Furthermore, the target waveform cannot be input to the vibration system as it is, and a problem arises that a new waveform for reducing the gain must be created for testing. This is complicated and time-consuming in programming.

Further, since the device disclosed in Japanese Patent Laid-Open No. 2-134559 is a device for measuring the vibration of a material, the output vibration waveform is not corrected and reproduced. In addition, a plate with holes is required to collect the sound waves generated by the sound wave generator.

The present invention is to solve the above-mentioned problems and provides a simple apparatus which does not require a large-scale apparatus or a complicated program by generating vibrations by sound waves, and further provides an inverse transfer function. By calculating using
It is an object of the present invention to provide a testing machine which can correct an output waveform and reproduce a vibration waveform close to a set vibration waveform.

[0010]

In a vibration reproducing apparatus using a sound wave according to the present invention, a vibrating device having a sound wave generator for generating a sound wave and an object to be vibrated by receiving the sound wave of the sound wave transmitter is provided. A vibration measurement storage means for recording and storing a vibration measured in advance; an A / D conversion means for converting an analog signal output from the vibration measurement storage means into a digital signal; The digital signal converted by the A / D conversion means is input, the inverse transfer function obtained in advance is calculated as a correction value, and the calculation means for outputting the corrected vibration waveform, and the digital signal output by the calculation means are calculated. It is composed of D / A conversion means for converting into an analog signal.

It is sufficient that the sound wave transmitter and the vibrating body are not in contact with each other.

Further, it is more preferable that the vibrating body is formed in a thin plate shape that can be excited by air propagation.

[0013]

In the vibration reproducing apparatus using sound waves according to the first aspect of the present invention, the vibrating device is configured by using the sound wave generator, and the preset vibration waveform is corrected by the inverse transfer function obtained in advance. Since it is calculated as a value and the corrected waveform corrected is output, the vibration reproducing device can be configured with an extremely simple device, and a waveform close to the target waveform can be obtained.

In the vibration reproducing apparatus using sound waves of the second aspect, since the sound wave generator of the vibration device and the vibrating body are installed in a non-contact manner, the apparatus can be easily set.

In the vibration reproducing apparatus using sound waves according to the third aspect, since the vibrating body of the vibrating device is formed in the shape of a thin plate that can be air-electroplated, a simple apparatus using sound waves can be provided.

[0016]

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

FIG. 1 shows a vibrating device 1 as a vibrating system according to the present invention.
The whole system including is shown.

Speaker 2 as a sound wave generator on the floor
Is placed. Above the speaker 2, a water tank 3 is supported on the floor via a vibration isolator 4. The speaker 2 and the water tank 3 are in non-contact with each other.

The agitated portion of the water tank 3 is formed in a thin plate shape so that the vibration of the speaker 2 is propagated.

In order to detect the vibration transmitted to the water tank 3,
A pickup 5 as a sensor is arranged via a support 6 supported by the bottom plate of the water tank 3.

The pickup 5 is connected to a pollution vibration meter 7 and is connected from the pollution vibration meter 7 to a level recorder 8 as a recording medium. Further, the signal output from the pollution vibrometer 7 is input to the personal computer 13 of the control system as an arithmetic unit through the A / D converter 9, and the A / D converter 9 also includes a DAT as a vibration measurement storage device.
10 are connected.

On the other hand, the speaker 2 has an amplifier 11 and D /
It is connected to the personal computer 13 via the A converter 12, and generates a sound wave in response to an instruction from the personal computer 13.

Next, the control system 13 will be described with reference to the block diagram of FIG.

Reference numeral 14 is a target waveform, which is input to the vibration system 1 described above. The target waveform 14 input to the vibration system 1 is output and output as the target response waveform 15.

The target waveform 14 and the target response waveform 15 are transformed from the time domain to the frequency domain by the Fourier transform means 16 and are represented as a target waveform spectrum 17 and a target response waveform spectrum 18, respectively.

Reference numeral 19 denotes an inverse transfer function calculating means, which calculates an inverse transfer function 20 from the target waveform spectrum 17 and the target response waveform spectrum 18.

Reference numeral 21 denotes a modified waveform spectrum calculation means, which calculates a modified waveform spectrum 22 from the inverse transfer function 20 calculated by the inverse transfer function calculation means 19 and the target waveform spectrum.

The modified waveform spectrum 22 is transformed from the frequency domain to the time domain by the Fourier transform means 23 to represent a modified waveform 24.

The corrected waveform 24 is input to the vibration system 1 again,
The corrected response waveform 25 is output. Modified response waveform 25
Is Fourier transformed by the Fourier transforming means 16 and represented as a modified response waveform spectrum.

The modified response waveform 25, which is the final vibration waveform modified and reproduced, may be the same as the target waveform 14, and the modified response waveform spectrum 26 may be the same as the target waveform spectrum 17.

Next, the operation of the vibration reproducing apparatus using this sound wave and the procedure for correcting the waveform will be described with reference to FIGS.

The target waveform 14 shown in FIG. 2 is a waveform diagram showing the construction vibration of the sheet pile when using Pulsonic, and the waveform of the construction vibration temporarily stored in the DAT 10 is the A / D converter. Is stored in the personal computer 13 as a target waveform memory (not shown).

The target waveform 14 is converted into analog by the D / A converter 12, amplified by the amplifier 11, and transmitted to the speaker 2.

The sound wave generated from the speaker 2 is transmitted to the water tank 3 by air. Since the water tank 3 is supported via the floor surface and the vibration isolator 4, the vibration transmitted to the water tank 3 is not transmitted to the floor surface and is directly output as the vibration of the water tank.

The vibration detected by the pickup 5 is displayed by the level recorder 8 connected to the pollution vibrometer 7 while the vibration value is displayed, and is converted from analog to digital by the A / D converter 9.

On the other hand, the digitally converted signal is temporarily stored as a target response waveform memory (not shown). However, as is clear from FIG. 2, the target response waveform 15 is the target waveform 1
It can be seen that it is changed compared to 4.

Next, the procedure for calculating the corrected waveform will be described with reference to FIG. 3. The construction vibration record and the construction vibration reproduction are represented by the target waveform K (t), and the response record is represented by the target response waveform O (t).

Target waveform K (t) and target response waveform O
Fourier transform means Fourier transforms (t) into a target waveform spectrum K (p) and a target response waveform spectrum O (p), respectively.

Then, the inverse transfer function and the modified waveform spectrum are calculated by the inverse transfer function calculating means and the modified waveform spectrum calculating means.

First, the transfer function is calculated. The transfer function is calculated by the following formula: transfer function D (p) = target response waveform spectrum O (p) / target waveform spectrum K (p).
The inverse transfer function is inverse transfer function G (p) = 1 / transfer function D
It is calculated based on the calculation formula (p).

When the inverse transfer function is obtained, the corrected waveform spectrum is created as the corrected oscillation based on the formula of the corrected waveform spectrum C (p) = the target waveform spectrum K (p) * the inverse transfer function G (p). .

The modified waveform spectrum C (p) is converted into the modified waveform C (t) by the inverse Fourier transform means.

The converted corrected waveform is sent again to the vibrometer for reproduction, and the corrected response waveform is compared with the target waveform. As is clear from the waveform diagram shown in FIG. 2, the modified response waveform is represented almost the same as the target waveform. This comparison is done visually.

In this comparison, not only the target waveform and the modified response waveform but also the target waveform spectrum and the modified response waveform spectrum obtained by Fourier transforming the modified response waveform are compared. In FIG. 2, it can be seen that the modified response waveform spectrum and the target waveform spectrum are almost the same.

In this way, the vibration is reproduced by the sound wave,
If the vibration is corrected using the inverse transfer function, it is possible to reproduce a vibration waveform quite close to the target waveform.

The above calculation may be performed once unless the vibrating body of the vibration placing device is changed. As described above, in the device of the present invention, if the set vibration waveform is corrected once by the calculating means, it is simply reproduced and compared, which is extremely simple.

The apparatus shown in FIG. 4 uses a thin acrylic plate 27 instead of the water tank 3 in FIG. As a result, as in the case of using the water tank 3, the corrected response waveform and the corrected response waveform spectrum showed a target waveform and a waveform substantially similar to the target waveform spectrum.

[Brief description of drawings]

FIG. 1 is a diagram showing the whole of a vibration reproducing apparatus using sound waves of the present invention.

FIG. 2 is a diagram showing a control system of a vibration reproducing device using sound waves of the present invention.

FIG. 3 is an explanatory diagram showing a flow of calculation of corrected vibration.

FIG. 4 is another embodiment of the vibration device.

FIG. 5: Conventional example of vibration correction device

FIG. 6 Conventional example of vibrating device by sound wave

[Explanation of symbols]

1 ... Vibration device 2 ... speaker 3 ... water tank 5 ... Pickup 7 ... Vibration meter 10 ... Vibration measurement storage device (DAT) 13 ... Personal computer (calculation means) 14: Target waveform 15: Target response waveform 16 ... Fourier transform means 17: Target waveform spectrum 18: Target response waveform spectrum 19 ... Inverse transfer function calculation means 20 ... Inverse transfer function 21 ... Corrected waveform spectrum calculation means 22: Modified waveform spectrum 23 ... Fourier inverse transforming means 24: Corrected waveform 25: Modified response waveform 26: Modified response waveform spectrum

Continuation of the front page (56) Reference JP-A-2-134559 (JP, A) JP-A-8-278219 (JP, A) JP-A-60-254211 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G01M 7/02 G05D 19/02

Claims (3)

(57) [Claims] 1. A vibrating device having a sound wave generator for generating a sound wave and a vibrating body vibrated by receiving the sound wave of the sound wave generator, and a vibration measurement memory for recording and storing vibration measured in advance. Means and A / D conversion means for converting the analog signal output from the vibration measurement storage means into a digital signal, and the digital signal sent from the vibration measurement storage means and converted by the A / D conversion means are input in advance. The inverse transfer function is calculated as a correction value, and the calculation means outputs the corrected vibration waveform, and the D / A conversion means converts the digital signal output by the calculation means into an analog signal. A vibration reproduction device using sound waves. 2. The vibration reproducing apparatus using sound waves according to claim 1, wherein the sound wave transmitter and the vibrating body are not in contact with each other. 3. A vibration reproducing apparatus using a sound wave, wherein the vibrating body according to claim 1 is formed in a thin plate shape that can be excited by air propagation.