JPS6361122A - Acoustic intensity wattmeter - Google Patents

Abstract

PURPOSE:To accurately measure the position and intensity of a sound source, by providing a pair of sensors so as not only to cross the extending direction of a pair of other sensors almost at a right angle but also to pass the center between said sensors and making all of sensors rotatable. CONSTITUTION:Sensors 1, 2 and sensors 3, 4 are provided in opposed relationship so as to cross each other at a right angle in order to respectively measure x- and y-components and supported in a rotary mechanism part 5 so as to hold definite intervals therebetween and rotate on an xy-plane. When the magnitude of the intensity of an objective sound source is measured, said sensors are rotated so that only a pair of the sensors are turned to the sound source to perform measurement and, since a pair of the other sensors are disconnected at the input change-over contact provided in the mechanism part 5, the error due to the effect of a sonic wave other than the sonic wave of the sound source can be removed. Since a direction best in sensitivity is allowed to coincide with a reference axis (x, y axis) by rotating the sensors 1-4 and the outputs of the sensors 1-4 can be inputted to an operation part through four input change-over contacts, directional searching becomes possible around a reference axis direction at the time of the searching of the sound source direction and the efficiency and accuracy in the searching of the main sound source can be enhanced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an acoustic intensity wattmeter having a sensor section for sensing sound waves, an intensity calculation section, and a display section, and particularly relates to an acoustic intensity wattmeter having a sensor section for sensing sound waves, an intensity calculation section, and a display section. This invention relates to an acoustic intensity wattmeter suitable for exploration.

[Conventional technology]

In order to implement noise countermeasures for equipment, etc. in a short period of time and economically,
High-precision detection technology for noise sources is essential, and acoustic intensity wattmeters have recently attracted attention as a measuring device for this purpose. Conventionally, this type of wattmeter has a pair of sonic sensor sections that are arranged opposite to each other, a support section that supports these sonic sensor sections, and a signal from the sonic sensor section that takes in signals and determines the magnitude and direction of the intensity. There is a known device that consists of an intensity calculation unit that performs calculations and a display unit that shows the magnitude and direction of the intensity of the calculation result of the intensity calculation unit (Institute of Industrial Science, University of Tokyo, “ Chief complaint leaflet J, Nα, 12
4. Simple sound intensity calculation unit).

Further, although there are examples in which the above-mentioned acoustic intensity wattmeter is commercialized and provided, the sound wave sensor section is composed of only one pair of sensors.

[Problem that the invention seeks to solve]

The above conventional technology basically measures the direction and magnitude of the intensity in the direction of the extension axis connecting a pair of sensors, and when detecting the direction of the sound source position, , the sensor needs to be rotated 180 degrees. In this case, the magnitude of the intensity for each sensor must be memorized and the direction of the sound source position must be determined. In such cases, it is either impossible to apply, or even if it is applied, the accuracy is extremely poor.

To solve this problem, an acoustic intensity wattmeter has been proposed that has two pairs of sonic sensor sections orthogonal to each other. In the intensity wattmeter, the direction and magnitude of the intensity can be immediately obtained from the calculation results of the magnitude and direction of the intensity obtained using each pair of sensor output signals. However, if one pair of sensor parts is installed in the extending direction of the support, and another pair of sensor parts is installed that passes through the center and intersects at right angles, the sensor part There has been a problem in that the accuracy of the directionality of the sound waves is poor because the sensitivity in the middle of adjacent sensor sections that are orthogonal to each other is better than the sensitivity in the extension direction.

Therefore, when trying to measure the intensity of a sound source more accurately, it is necessary to point the sensor unit in the direction of the target sound source and measure the intensity from the front direction of the target sound source. In addition to the intensity from a pair of sensor sections facing the direction of the target sound source, an acoustic intensity wattmeter with a section also calculates the intensity from another pair of sensor sections orthogonal to the sensor section. It was easily influenced by sources other than the target sound source, and there was a problem with the accuracy of the intensity of the target sound source.

An object of the present invention is to provide an acoustic intensity measurement system that can measure the direction and magnitude of sound intensity with high accuracy in a short period of time, detect the position of a sound source, and measure the intensity of a target sound source more accurately. Our goal is to provide a city watt meter.

[Means for solving problems]

The present invention, which has achieved the above objects, includes: a sensor section that takes in sound waves and converts them into acoustic signals; an acoustic intensity calculation section that takes in the acoustic signals from the sensor section and calculates the direction and intensity; In the acoustic intensity wattmeter, the sound intensity wattmeter includes a display section that displays the results of calculation processing performed by the sensor section, wherein a pair of the sensors is provided, the sensor is arranged substantially perpendicular to the extension direction of the pair of sensors, and passes through the center of the pair of sensors. A pair of sensors is provided as shown in FIG. This feature is characterized in that it is configured to be input into the section.

[Effect]

When detecting the position of a sound source, the propagation direction of the sound wave is determined by calculating the intensity of the signals collected by two pairs of sensors.
It is calculated based on the magnitude ratio, sign, and magnitude relationship of these output signals, and the most sensitive direction on the two pairs of sensor configuration planes is aligned with the reference axis, for example, the X-Y axis. This enables more reliable sound source detection.

Furthermore, when measuring the intensity of a target sound source, intensity calculation is performed on only the signals of the pair of sensors directed toward the target sound source so that only the intensity from the direction of the target sound source is measured.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows an external view of the intensity wattmeter.

The wattmeter includes sensors 1 to 4, a rotation mechanism section 5 that supports the sensors and rotates on a plane, a support 6 for supporting the one-rotation mechanism section 5, and a display section 7 that supports one end of the support 6. A calculation unit box 11 for accommodating an intensity calculation circuit unit 9 and a power supply unit 10, and a communication cable 12 between the one-hand box unit 8 and the calculation box unit 11.

Sensors 1 and 2 are sensors for measuring the intensity of the X component in the same direction as the axial direction of the support 6, and sensor 3
and 4 are sensors for measuring the intensity of the X component in the direction orthogonal to the axis of the support 6. Sensors 1 and 2 and sensors 3 and 4 are provided facing each other and orthogonal to each other, and these sensors 1 to 4 are small electret microphones. The rotation mechanism section 5 has sensors 1 and 2.
It has the function of rotating on the xy plane around the intersection of sensors 1 and 2 and sensors 3 and 4 while supporting sensors 3 and 4, and also maintains a constant spacing between these sensors. It has a function that can output all the signals of sensors 1 to 4, or the signals of sensors 1 and 2 or sensors 3 and 4.

FIG. 2 is a block diagram showing an intensity calculation circuit section and a display section.

This circuit includes a buffer section 13 for amplifying the outputs A and A of sensors 1 and 2, outputs B and 101 of the other pair of sensors 3 and 4, and performing impedance matching. A circuit 14 that calculates intensity components X and Y in the X and y directions from the signals of It is composed of a circuit 17 and a circuit 20 including LED display sections 18 and 19 that display the magnitude and vector using LEDs.

The intensities Ix and Iv in the X and y directions are the sound pressure P (t) and particle velocity v (
t). here.

Since the particle velocity v (t) is proportional to the spatial gradient of the sound pressure of the two sensor signals, the calculation shown in the following equation is realized by an electric circuit.

Here, e is the air density, Δr1 and Δrz are the distances between each pair of sensors, and P! ~P4 indicates the output sound pressure of sensors 1 to 4.

FIG. 3 is an enlarged plan view of the display unit 7 housed in the hand box 8. In FIG. ing. Further, an LED 22 for displaying the intensity level is also provided at the center of these LEDs.

Here, if the incident angle of the sound wave is α, the intensity X-axis and y-axis components Ix and Iv are as follows. size I
I+ is as follows, and the angle α can be found from tanα=l IY/IX 1 or cota=I Ix/Iv 1 and the sign relationship between χ and Iv.

FIG. 4 is a block diagram showing an embodiment of a calculation section for determining the direction of incidence of sound.

In this embodiment, the entire circumference is divided into 36 parts at a pitch of 10 degrees for calculation and display. A divider 23 divides the signal IIxl after the intensity calculation, which is collected by the two pairs of sensors 1 to 4, and IIYI. In this case, divider 23 is obtained by comparator 24. 1Ix
Calculation is performed based on the result of determining whether l and IIYI are large or small. The value from the divider 23 and the output value from the angle equivalent voltage generation circuit 25 are compared by comparators 26 to 29, and the results of these comparisons are input to the memory 3o as a 4-bit (bit) digital signal. On the other hand, O≦lIv/I x
The display area in the direction corresponding to l≦1 or 0≦IIX/IY+≦1 is 8 areas obtained by dividing 360 degrees in all directions into 8 areas, so in order to specify a certain area from among these, the comparator 24 and the code are used. Inversion circuits 31 and 32 and sign discrimination circuit 3
3, 34, 35°36, Ix, -Ix,
Digital conversion is performed into signals representing the respective codes of IY-Iy and the magnitudes of Ix and IY. These signals and 4 above
When the bit signal is input to the memory 3o as an address.

Binary signals (
6bit <1', 2', 4', 8'.

16', 32'>) are output. The decoder 37 and driver circuit 38 in this block diagram are a circuit for converting a binary number into at least a 36-decimal number, and a circuit for driving an LED in a direction corresponding to this output.

FIG. 5 is a diagram showing the directivity characteristics of a pair of sensors 1 and 2 provided in the axial direction (X direction) of the support 6. 1
It can be seen that in the case of a pair of sensors, the sensitivity is good in the axial direction.

FIG. 6 shows the directional characteristics when another pair of sensors 3 and 4 are provided perpendicularly to the pair of sensors 1 and 2 in the X-axis direction shown in FIG. In this case, it can be seen that the sensitivity is improved in the region where the two pairs of directional characteristics overlap. Therefore, in the case of intensity measurement at the sensor position shown in Figure 6, for sound waves incident from the X-axis direction, the sound source direction indication does not accurately indicate the X-axis direction, and the directional characteristics of each sensor overlap. FIG. 3 is a diagram showing a direction with good sensitivity.

Figure 7 shows the directivity characteristics when the two pairs of sensor positions shown in Figure 6 are rotated around the intersection of the two pairs of sensors so that the most sensitive direction matches the X and Y axes. FIG.

This embodiment has a function to rotate the sensor direction around the intersection of two orthogonal pairs of sensors, which improves the accuracy of direction indication in the reference axes (X-axis, y-axis) direction in sound source direction detection. This makes it easy to locate the sound source.

Figure 8 shows the positions of the input signal switching contacts provided in the input signal circuit and the rotation mechanism when the two pairs of sensors 1 and 2 and sensors 3 and 4 are oriented in the X-axis and y-axis directions, respectively. This is a diagram. The signals collected from sensors 1 and 2 in the X-axis direction pass through contacts provided on the circuit connecting the sensors and the calculation section, and are output as outputs A and A to the buffer section 13 for amplification and impedance matching shown in FIG. is input to. y#1
Direction sensors 3 and 4 are disconnected at the human power signal switching contact position, so outputs B and I3 become 0, and output A
, A are used to perform the intensity calculation. When measuring the intensity of a target sound source, it is sufficient to measure the intensity using a pair of sensors directed toward the target sound source, and another pair perpendicular to this.
Inputs from the paired sensors are not required and are susceptible to errors due to the influence of sound waves other than the target sound source. Therefore, when measuring the intensity of a target sound source, the structure is such that intensity measurement can be performed using only one pair of sensors.

FIG. 9 shows an input signal circuit diagram when the most sensitive direction of two pairs of sensors 1 to 4 orthogonal to each other is aligned with the reference axis (x@+y axis). The input signals from sensors 1 and 2 and sensors 3 and 4 pass through the input switching contact provided in the one-rotation mechanism section, and intensity calculation is executed as outputs A, τ and outputs B, . From the y-axis components Ix and Iv, the sound incidence direction is calculated by the arithmetic unit block shown in FIG. 4 and displayed on the display section 7 shown in FIG. 3. In this case, since the direction in which the two pairs of sensors have the highest sensitivity coincides with the reference axes, which are the This improves the efficiency and accuracy of sound source search.

Now, one embodiment of the rotation mechanism section 5 and its input signal switching contact section will be described with reference to FIGS. 10 to 13.

FIG. 10 is a perspective view showing the appearance of the rotation mechanism section.

FIG. 11 is a sectional view showing the internal structure of the rotation mechanism shown in FIG. 10.

In these figures, sensors 1 and 2 are fixed to a rotating mechanism section 5, and by rotating the rotating mechanism section 5, the sensors 1 and 2 also rotate in the same direction. The rotation mechanism section 5 is supported by a support 6 and is rotated by a sliding section 39 provided between the rotation mechanism section 5 and the support 6. Input signals from the sensors 1 and 2 are transmitted to the input signal contact sections 44 and 45 and supplied to the intensity calculation circuit section 9 as outputs A and τ. Input signal contact section 44
and 45 are brought into close contact with the input signal switching contact portions 44 to 47 by the urging force of springs 42 and 43. Output signal B
, B can also be obtained by a similar mechanism.

FIGS. 12 and 13 are cross-sectional views showing the rotation mechanism section.

FIG. 12 shows a case where the directions of sensors 1 and 2 are aligned with the y-axis, which is the reference axis, and the sensors 3 and 4 are oriented in the y-axis direction. In this case, input signals from sensors 1 and 2 are transmitted to input signal contact sections 44 and 45 via input signal switching contact sections 40 and 41. Sensors 3 and 4 in the y-axis direction
The input signal from is transmitted to the input signal switching contact parts 49 and 51, but since the installation positions of the input signal contact parts 46 and 52 are not on the y-axis, the input signal switching contact parts 49 and 5
The signals from sensors 3 and 4 that are not in contact with sensor 1 are not output to the calculation unit.
Only the output signals A, A from and 2 are transmitted. Stoppers 53 and 54 fixed to the support 6 are provided to align the sensors 1 and 2 and the sensors 3 and 4 with the y-axis, which is the reference axis, and the y-axis direction.

Figure 13 shows sensors 1 and 2 and sensors 3 and 4
Rotation mechanism part 5 when rotated by 45 degrees with respect to the axis and y axis
FIG.

Input signals from sensors 1 and 2 and sensors 3 and 4 are transmitted from input signal switching contacts 40 and 41 and 51 and 49 to input signal contacts 44 and 45 and 52 and 46, resulting in output signal A.

The signals are supplied as X, B, and B to the intensity calculation circuit section 9.

By providing the rotation mechanism 5 in this way and rotating the sensor section, it becomes possible to transmit input signals from one pair of sensors or human power signals from two pairs of sensors to the calculation section.

In this embodiment, an input signal switching contact is provided in the circuit mechanism section 5 shown in FIG. 1, but the input signal switching is not limited to this, and the input signal switching is not limited to this. The present invention also includes a case where the input signal is inputted using two pairs of sensors or only one pair of sensors. In addition, the intensity calculation using only one pair of sensors is not limited to one determined by the input signal switching contact as shown in this embodiment, but may be controlled by the circuit vf14 or circuit 17 shown in the second example. Those that are also included in the present invention. Furthermore, the positions and numbers of the input signal switching contacts shown in this embodiment are not limited to these, and the present invention also includes a plurality of contacts and their positions.

〔Effect of the invention〕

As described above, according to the present invention, in an acoustic intensity wattmeter having two pairs of sound wave sensors, two
By rotating the directions of the two pairs of sensors on the x-y axis plane using a rotation mechanism centered at the intersection of the pair of sensors, the direction with the most sensitive direction of the directional characteristics generated by the two pairs of sensors is used as the direction indication standard. Since it can be aligned to the axes (y-axis and y-axis), when searching for the main sound source from among multiple sound sources, the accuracy of direction indication in the reference axis direction, which is easiest to grasp the direction of the sound source, is greatly improved, and the direction of the sound source is This has the effect of improving exploration efficiency.

Further, according to the present invention, when the two pairs of sensors that are orthogonal to each other are aligned on the basic axis by the rotation mechanism,
Sound intensity can be calculated using only input signals from a pair of sensors, so when measuring the intensity of a target sound source, by pointing the fundamental axis of the target sound source, the pair of sensors in that direction can be calculated. Since the intensity can be measured based on the sound source, errors caused by the influence of sound sources other than the target sound source can be removed, and the intensity can be measured with high accuracy.

[Brief explanation of drawings]

FIG. 1 is an external perspective view showing an acoustic intensity wattmeter according to an embodiment of the present invention, FIG. 2 is a block diagram showing an intensity calculation circuit section and a display section, and FIG. 3 is an enlarged view of the display section. The plan view, Figure 4 is a block diagram showing the sound incident direction calculation circuit, Figure 5 is a directional characteristic line for one pair of sensors, and Figures 6 and 7m are directional characteristic lines for two pairs of sensors. 8 and 9 are circuit diagrams showing the states of input signals in the case of FIGS. 5 and 7, FIG. 10 is an external perspective view showing an example of the configuration of the rotation mechanism, and FIG. 11 is a rotation FIGS. 12 and 13 are an external perspective view showing the inside of the mechanism section with a part cut away, and sectional views showing the rotation mechanism section. 1 to 4...sensor, 5...rotation mechanism section, 7...display section. 8... Hand box part, 9... Intensity calculation circuit/structure part, 11... Calculation box part, 13... Buffer part for amplification and impedance matching, 14... Intensity component calculation circuit, 17... Direction and size calculation circuit, 20... LED display section circuit, 40... Input signal switching contact section, 42... Spring, 44... Input signal contact section.

Claims (1)

[Claims] 1. A sensor section that takes in sound waves and converts them into acoustic signals; an acoustic intensity calculation section that takes in the acoustic signals from the sensor section and processes the direction and intensity; and a result of the calculation processing performed by the acoustic intensity calculation section. A sound intensity wattmeter comprising a display section for displaying information, wherein a pair of the sensors is provided, and the pair of sensors is arranged so as to be substantially orthogonal to the extension direction of the pair of sensors and to pass through the center of the pair of sensors. and a rotation mechanism capable of rotating the two pairs of sensors, and configured to input only the acoustic signals from the two pairs of sensor sections or the acoustic signal from the one pair of sensor sections to the acoustic intensity calculation section. Sound intensity wattmeter featuring: