JPS586135B2 - acoustic holography device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an acoustic holography device.

Acoustic holography equipment, which searches for sound sources in mechanical devices using sound wave analysis, records the sound waves of the measured object (the sound source) as data on the hologram surface using a signal microphone and a reference wave microphone, and then compares the signal wave with the reference wave. Through analysis using interference, a sound image is reproduced on a plane containing the object to be measured.

However, it has not been easy to simply and accurately correspond between the reproduced sound image and the position and shape of the object to be measured.

The present invention has been made based on the above-mentioned circumstances, and provides an acoustic holography device that can easily and accurately correspond between a reproduced sound image and the position and shape of an object to be measured.

The invention will be explained in detail below with reference to the drawings.

In the figure, one or several reference speakers 3 are installed on a plane 2 containing an object to be measured 1 at positions that clearly correspond to the position and shape of the object to be measured.

For example, one point is installed at a position 1 m apart in the horizontal direction from a point A with a characteristic shape of the object to be measured 1, and 1 m in the vertical direction.
Install one in a separate location.

These reference speakers 3 are driven by an oscillator 4 at a frequency that does not overlap with the frequency band of the sound waves emitted by the object to be measured 1 .

On the other hand, 5 is a signal microphone that scans the inside of the hologram plane 6 parallel to the plane 2, and 7 is a reference wave microphone installed at a position different from the hologram plane (or even within the hologram plane). It's a microphone.

The outputs of these microphones are signal processed in a manner similar to that in known acoustic holography devices.

According to the apparatus of the present invention having the above configuration, the sound waves emitted from the object to be measured 1 and the reference speaker 3 are recorded as data on the hologram surface 6 by the microphones 5 and 7.

The recorded data is reproduced as a sound image on a plane corresponding to the plane 2 including the object to be measured 1 by analysis using interference between the signal wave and the reference wave.

At this time, since the sound image of the reference speaker 3 is also reproduced, the position of a point A on the sound image of the object to be measured 1, which has a characteristic shape, can be determined from the position of the sound image of the reference speaker 3. The correspondence between the position and shape of the measurement object 1 and the sound image is required.

Note that since the driving frequency of the reference speaker 3 is outside the frequency band of the sound waves generated by the object to be measured 1, the influence of the reference speaker 3 on the sound image of the object to be measured is small, and there is no problem in practical use.

In addition, by photographing the plane 2 including the object to be measured 1 using a camera or TV camera, and matching the position of the sound image of the reference speaker 3 with the position of the reference speaker in the photographed image, Position and shape of object 1 and measured object 1
The correspondence with the sound image can be seen more clearly.

As is clear from the above, according to the apparatus of the present invention, correspondence between the reproduced sound image and the position and shape of the object to be measured can be easily and accurately performed.

[Brief explanation of the drawing]

The figure is a schematic perspective view of one embodiment of the present invention. 1...Object to be measured, 2...Plane containing the object to be measured, 3...Reference speaker, 4...
Oscillator, 5...Signal microphone, 6.
...Hologram surface, 7...Reference wave microphone.

Claims (1)

[Claims] 1 A signal microphone that scans within the hologram plane,
In a device that is equipped with a reference wave microphone at a fixed position and processes the output of these microphones to obtain an acoustic honogram, a predetermined point is placed on a plane parallel to the honogram plane and containing the object to be measured from a point unique to the shape of the object to be measured. An acoustic honography device comprising one or more reference speakers spaced apart and driven at a frequency outside the frequency band of sound waves emitted by an object to be measured.