JP2007240292A - Sound simulation system for building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simulation system, capable of obtaining proper results that are almost same as the actual measurement, by simply calculating the sound environment of building having many walls. <P>SOLUTION: The sound simulation system is such that a first constitution of the simulation system comprises the input means for inputting the building information, having a first wall between the sound source space and transmission space, sound source information and sound-receiving point information; a first calculation means for calculating the energy which is received by each reference surface divided from the first wall in the sound source space, based on the information inputted by the input means; a second calculation means for calculating the sound level of temporary sound source of the transmission space side; and a third calculation means for operating the energy of the sound source radiated from the temporary sound source. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  This is a sound simulation of a building, and relates to a system that can output a result in consideration of wall penetration.

  Conventionally, sound transmission simulation using a computer has been performed.

  As a method for simulating the transmission of sound, the wave analysis method of difference method (FDM), finite element method (FEM), boundary element method (BEM), boundary integral equation method (BIEM) and the wave nature of sound It has been developed as a geometric analysis method that ignores and calculates as simple sound rays (Sound Rays) or sound particles (SoundParticles).

  In particular, wave analysis methods have been developed for the purpose of obtaining solutions to complex problems in order to faithfully calculate the wave nature of sound, but it is necessary to use enormous computer resources for computation. There's a problem.

  Geometric analysis methods ignoring sound diffraction and transmission have been developed as effective means of finding spatial solutions in an approximate and quick manner. There is a problem that only a solution in space can be obtained. The geometric analysis method is generally called a sound ray method and has been developed as a sound ray tracking method or a virtual image method.

  The ray tracing method is a method in which a large number of ray rays are radiated from a set point sound source to the entire space, and the reflection history, energy, and incident direction data are sequentially calculated. This is a method of calculating and calculating the reflection history of the sound ray by searching for the reflection surface path of the line and providing an imaginary sound source. The virtual image method is more accurate in direction, relative intensity, and arrival time than the ray tracing method, but the total number of imaginary sound sources increases exponentially as the reflection order increases, so even higher-order reflections can be achieved. It is difficult to calculate.

  However, the sound ray method is known to be an effective means for simulating the sound environment because the calculation is simple and the amount of calculation is small compared to the wave analysis method. In particular, it is suitable for quick and simple analysis of a closed space. For example, it is possible to obtain a simple and good simulation result in combination with the virtual image method as disclosed in JP-A-6-11386. It has become.

JP-A-6-11386

  However, the sound ray method, as described above, seeks to transmit sound by reflection in principle, and ignores the wave nature of sound. For this reason, although it is suitable for the simulation of a closed space, when a barrier such as a wall exists in the space, the sound ray cannot cross the barrier.

  On the other hand, considering the simulation of sound transmission in a house, unlike a simple space such as a hall, a house is a complex space with many barriers such as walls and partitions. I can't.

  For this reason, conventionally, wave analysis techniques have been used in complex spaces such as houses, but due to the low computational load, proposals have been made for analysis through a barrier in the sound ray method. For example, a sound ray path is calculated assuming that there is no barrier, and then a sound ray path reflected from the intersection of the barrier and the sound ray is calculated. Then, similarly to the attenuation of sound pressure due to reflection, it is conceivable to calculate the sound transmitted across the barrier by calculating the attenuation of sound pressure due to transmission. However, since the sound is a wave, the vector of the sound ray should have been lost when the barrier was crossed.

  Therefore, it is conceivable to set a temporary sound source on the surface opposite to the intersection of the barriers at the intersection (reflection point) between the barrier and the sound ray. However, although it is usually a simple calculation for one sound source, setting a temporary sound source for each intersection and computing the omnidirectional sound ray in the same way as a normal sound source requires a large amount of calculation. The advantage of the ray method, which increases dramatically and is simple to calculate, is significantly impaired.

  Accordingly, an object of the present invention is to provide a simulation system that can easily calculate the sound environment of a building with many barriers and obtain a good result close to an actual measurement value.

  In order to solve the above problems, a first configuration of a building sound simulation system according to the present invention includes building information having a first barrier between a sound source space and a transmission space, sound source information, and a sound receiving point. And a first calculation for calculating energy received by each reference plane obtained by dividing the first barrier from the sound source in the sound source space based on the information input by the input means. Means, second computing means for computing the sound pressure level of the temporary sound source on the transmission space side based on the energy received by the sound source space side of the reference plane computed by the first computing means, and the temporary sound source And third calculating means for calculating the energy of the sound ray radiated from.

  According to a second configuration of the building sound simulation system of the present invention, in the first configuration, a point of a second reference plane obtained by dividing the inner surface of the transmission space from the temporary sound source into a plurality of points, and the temporary sound source. It has the 4th calculating means which calculates the energy of the sound ray radiated | emitted directly to the said sound receiving point, It is characterized by the above-mentioned.

  According to a third configuration of the building sound simulation system of the present invention, in the second configuration, a sound ray that is reflected by the second reference plane and reaches the sound receiving point and directly reaches the sound receiving point. It has the 5th calculating means which calculates a sound pressure level along the path | route about a sound ray, It is characterized by the above-mentioned.

  According to a fourth configuration of the building sound simulation system of the present invention, in any one of the first to third configurations, the first barrier is a virtual barrier set virtually, and the sound source space and the transmission The space is a virtual space that is temporarily separated.

  According to the first configuration of the building sound simulation system of the present invention, it is possible to easily calculate the sound environment of a building with many barriers and obtain a good result close to an actual measurement value.

  Moreover, according to the 2nd and 3rd structure of the building sound simulation system which concerns on this invention, it can calculate still more easily.

  In addition, according to the fourth configuration of the building sound simulation system of the present invention, the sound environment of a building having a complicated shape such as a U-shape is simply calculated, and a good result close to an actual measurement value is obtained. be able to.

  A building sound simulation system according to the present invention will be described. FIG. 1 is a schematic configuration diagram of a sound simulation system according to the present embodiment. FIG. 2 is a flowchart for explaining the characteristic operation of this embodiment. FIG. 3 is a diagram illustrating an example of setting a temporary sound source and a sound ray. FIG. 4 is a diagram showing an example of a transmittance / reflectance database.

(Configuration of building sound simulation system)
As shown in FIG. 1, the building sound simulation system includes a system main body 1, input means 2, and output means 3. The input unit 2 is a unit for inputting information necessary for calculation, and includes an input device such as a keyboard and a mouse, a storage medium, a network, and the like. The output means 3 outputs a calculation result, and includes a monitor for displaying a screen, a printer for printing, a recording medium for saving as data, and the like.

  The storage area 11 of the system main body 1 stores building information having a first barrier between the sound source space and the transmission space input from the input means 2, sound source information, and sound receiving point information.

  The building information includes spatial coordinate information such as the dimensions of the room (the sound source space 30 and the transmission space 31) and the thickness of the wall (first barrier 32, second barrier 33, etc.), and the wall (first barrier 32, The barrier information such as the material and type of the second barrier 33) is included. The sound source information includes the spatial coordinates (position) of the sound source and the characteristics of the sound source (frequency characteristics, directivity, intensity). The sound receiving point information includes spatial coordinates (position) for receiving sound pressure.

  Further, as shown in FIG. 4, the system main body 1 includes a transmittance / reflectance database 12 in which the transmittance is stored for the wall material and type. Note that the transmittance / reflectance database 12 does not necessarily have to be incorporated in the main body, and can be supplied by a recording medium such as a network type or a CDROM as necessary.

  Further, the system main body 1 has first to third calculation means 13 to 15. Each element of the system main body 1 is connected to the CPU 10 to perform predetermined processing. In practice, the storage area 11 is storage means such as a RAM or a hard disk, and the transmittance / reflectance database 12 is data stored in the storage means. The first to third arithmetic means 13 to 15 are modules realized by a program and read into the CPU 10 to perform a predetermined operation as hardware.

  Based on the information input by the input means 2, the first calculation means 13 calculates the energy received by each reference plane 32 a obtained by dividing the first barrier 32 from the sound source 34 in the sound source space 30. A specific calculation method is not particularly limited, and calculation methods such as a sound ray method and a virtual image method can be used. Further, by omitting a complicated calculation method, the energy received by each reference plane 32a is a predetermined value having a predetermined relationship with the sound source 34 or the sound source space 30 (for example, a value based on a transmittance with a set barrier). It may be calculated.

  Further, instead of the reference plane 32a, the content may be a point having no volume, or a space having a certain region around the point. That is, instead of the reference plane 32a, the energy received by the reference point set on the first barrier 32 from the sound source 34 may be calculated. Further, instead of the reference plane 32a, the energy received by the reference space set in the first barrier 32 from the sound source 34 may be calculated.

  In FIG. 2, the first barrier 32 is divided into 4 × 4 16 reference planes 32a. However, the number of divisions and the method are not limited thereto. For example, it may be divided into 4 × 8 32 reference planes 32a.

  Since the calculation method of the sound ray method is already well known, a detailed description is omitted here. Briefly, when only the sound ray method is used, first, a large number of sound rays are set at predetermined intervals from the sound source, and the intersections of the sound ray vectors and the walls are determined. Then, the direction of the sound ray to be reflected is determined according to the angle of the vector and the wall, and the next intersection is determined. If the reflection reaches a predetermined number of times, no further reflection is made (the end of the sound ray is the intersection with the wall). When the intersections and paths are determined for all sound rays, the sound pressure level is calculated along each path while considering attenuation due to distance and attenuation due to reflection. The calculation of the sound pressure level may be performed before the calculation of all the paths is completed (for example, every time one sound ray path is determined).

  However, since the sound ray method cannot accurately determine the direction, relative intensity, and arrival time, the virtual image method is often used when calculating the exact impulse response and convolving the dry source. . When the virtual image method is used, a sound receiving point is set, a virtual image of the sound source is created at a position symmetrical to the barrier, and the point where the sound ray connecting the virtual image and the sound receiving point intersects the barrier is defined as an intersection (reflection point). Ask. When considering two-time reflection and three-time reflection, first, a virtual image is created at a position symmetrical to the barrier that can be reflected, and then a virtual image of a virtual image is created for the barrier that can be reflected. In response, a superimposed virtual image is created. The calculation of the sound pressure level is the same as described above.

  The second calculation means 14 calculates the energy of the temporary sound source 35 on the transmission space side based on the energy received by the sound source space side of the reference plane 32a calculated by the first calculation means 13. Here, the temporary sound source refers to a sound source set on the wall surface in order to perform the calculation on the transmission space side 31.

  For example, as shown in FIG. 2, when the temporary sound source 35 is set at the center of four reference surfaces 32a, the energy of the temporary sound source 35 is the sum of the energy received by the four reference surfaces 32a. The value takes into account the transmittance of 32, etc.

  In the present embodiment, the configuration in which one temporary sound source 35 is provided for the four reference surfaces 32a has been described. However, the present invention is not limited to such a configuration. For example, the provisional sound source 35 may be set to be smaller than the number of reference surfaces 32a for a plurality of reference surfaces 32a, for example, two temporary sound sources 35 may be set for five reference surfaces 32a.

  Thereby, compared with the case where one temporary sound source 35 is set for one reference surface 32a, the amount of calculation can be reduced and the calculation can be performed easily. Even in this case, a good result close to the actually measured value can be obtained.

  The third computing means 15 computes the sound pressure level of the sound ray L emitted from the temporary sound source 35 and incident on the sound receiving point 36. The third calculation means 15 has fourth and fifth calculation means 16 and 17.

  The fourth computing means 16 is a sound radiated from the temporary sound source 35 to the point (second temporary sound source 33a1) of the second reference surface 33a obtained by dividing the inner surface (second barrier 33) of the transmission space 31 into a plurality. The energy of the line L1 and the energy of the sound line L2 radiated directly from the temporary sound source 35 to the sound receiving point 36 are calculated.

  The fifth computing means 17 includes a sound ray L3 that is reflected by the second reference surface 33a (radiated from the second temporary sound source 33a1) and reaches the sound receiving point 36, and a sound ray that directly reaches the sound receiving point 36. For L2, the sound pressure level is calculated along the path. Further, the fifth computing means 17 is reflected by the second reference surface 33a and further reflected by the second reference surface 33a (including the first reference surface 32a in the transmission space) several times to receive sound. For the sound ray reaching the point 36, the sound pressure level is calculated along the path.

(Operation of building sound simulation system)
Next, the operation of the building sound simulation system will be described with reference to FIG. As shown in FIG. 3, first, a sound source space 30 with a sound source and some transmission spaces 31 are discriminated (S1). Then, using the first calculation means 13, the energy received by each reference plane 32a from the sound source 34 in the sound source space 30 is calculated (S2).

  Next, the temporary sound source 35 is set using the second calculation means 14 (S3), and the temporary sound source is determined based on the energy received by the reference surface 32a, the number of reference surfaces 32a with respect to the temporary sound source 35, and the transmittance of the barrier 32. The energy of 35 is calculated (S4).

  Next, the fourth calculation means 16 is used to generate a point of the second reference surface 33a obtained by dividing the inner surface of the transmission space 31 into a plurality (S5). Then, a sound ray vector L1 connecting the temporary sound source 35 and the second reference plane 33a and a sound ray vector L2 connecting the temporary sound source 35 and the sound receiving point 36 are generated (S6).

  Next, of the generated sound ray vectors L1 and L2, one sound ray vector is specified, and it is determined whether it is the former sound ray vector L1 or the latter sound ray vector L2 (S7).

  When it is determined that the sound ray vector L2 is the latter in S7, the energy of each sound ray vector (received by the sound receiving point 36) is based on the distance of the latter sound ray vector L2, the air attenuation factor, and the energy of the temporary sound source 35. Energy) is calculated and integrated, and the calculation for the sound ray vector L2 is terminated (S7).

  Then, it is determined whether or not the calculation has been completed for all sound ray vectors (S9).

  If the former ray vector L1 is determined in S7, each ray vector is determined based on the distance of the former ray vector L1, the air attenuation rate, the transmittance / reflectance of the barrier 33, and the energy of the temporary sound source 35. (The energy received by the second reference surface 33a) is calculated and integrated (S10).

  Then, by using the fifth arithmetic means 17, it is determined whether or not the energy (integrated value) received by the second reference surface 33a is equal to or greater than a predetermined value to be calculated for the sound ray reflected by the second reference surface 33a. Judgment is made (S11). At this time, for example, in the case of the reference plane 32a that goes out from the inside of the building, 33a cannot be searched, so the calculation from 32a to 33a is not performed.

  If it is determined in S11 that the value is equal to or greater than the predetermined value, the point on the second reference surface 33a is set as a temporary sound source, and the process returns to S6. Then, a sound ray vector connecting the point of the second reference surface 33a (temporary sound source) and the point of the other second reference surface 33a, the point of the second reference surface 33a (temporary sound source), and the sound receiving point A sound ray vector connecting 36 is generated (S6).

  If it is determined in S11 that the value is less than the predetermined value, the calculation for the sound ray vector is terminated (S12). Then, it is determined whether or not the calculation has been completed for all sound ray vectors (S9).

  If it is determined in S9 that the calculation has not been completed for all sound ray vectors, the process returns to S6, and the calculation is performed for other sound ray vectors that have not been calculated (S7).

  If it is determined in S9 that the calculation has been completed for all sound ray vectors, the integrated value of the energy received by the sound receiving point 36 is converted into a sound pressure level, and the simulation is terminated.

  In the above operation (S11), the number of reflections of the sound ray on the second reference surface 33a is determined by the energy (integrated value) received by the second reference surface 33a. However, the present invention is limited to this configuration. Instead of this, it may be determined whether the number of reflections from the temporary sound source 35 has reached a predetermined number. As described above, since the number of reflections in S11 is limited, the increase in the sound ray vector converges early, and the calculation ends.

  In addition, although this embodiment demonstrated two rooms of sound source space and transmission space, this invention is not limited in the number of rooms. That is, the second temporary sound source 33a1 reflects the sound ray emitted from the temporary sound source 35 and transmits it to another room (transmission space). Then, the second calculation means sets a temporary sound source on the other room (transmission space) side based on the energy received by the point (temporary sound source) of the second reference plane 33a, and calculates the energy of this temporary sound source. To do.

  Further, the sound source space and the transmission space may be outside the building. That is, any one or more of the sound source space and the transmission space may be outside the building.

  As described above, the second calculating means 14 for calculating the energy of the temporary sound source 35 on the transmission space side based on the energy received by the sound source space side of the reference plane 32a calculated by the first calculating means 13 is provided. This makes it possible to reduce the amount of calculation compared to the method of setting a temporary sound source on the opposite surface for each intersection between the barrier and the sound ray, and for the sound ray that has lost the vector when the barrier is exceeded. The sound source 35 can be reproduced. Therefore, it is possible to easily calculate the sound environment of a building with many barriers and obtain a good result close to the actual measurement value.

  The sound ray vector is arranged so as to connect the temporary sound source 35, the sound receiving point 36, and the second reference point, and the second reference point, the sound receiving point 36, and the second reference point. Arranged to tie. Thereby, compared with the case where a sound ray vector is disperse | distributed by a predetermined angle, the density of a sound ray can be eliminated and the calculation efficiency can be improved. That is, since the sound ray vector surely enters the sound receiving point 36, unnecessary calculations that are not reflected in the simulation result can be omitted, and the sound environment of a building with many barriers can be calculated easily and good near measured values. Results can be obtained.

  The present invention can be used for sound simulation of buildings with many barriers such as houses.

It is a schematic block diagram of the sound simulation system which concerns on this embodiment. It is a block diagram of a building using a building sound simulation system. It is a flowchart explaining operation | movement of the sound simulation system of a building. It is a figure which shows the example of the transmittance | permeability and reflectance database.

Explanation of symbols

L ... Sound ray 1 ... System main body 2 ... Input means 3 ... Output means
11 ... Storage area
12… Transmission / Reflectance Database
13-17: First to fifth arithmetic means
30… Sound source space
31… Transparent space
32, 33… Barrier
32a, 33a ... 1st and 2nd reference plane
34… Sound source
35, 33a1 ... Temporary sound source
36… Sound receiving point

Claims (5)

Input means for inputting building information having a first barrier between the sound source space and the transmission space, sound source information, and sound receiving point information;
First computing means for computing energy received by each reference plane obtained by dividing the first barrier from the sound source in the sound source space based on the information input by the input means;
Second computing means for computing the energy of the temporary sound source on the transmission space side based on the energy received by the sound source space side of the reference plane computed by the first computing means;
Third calculating means for calculating the sound pressure level of the sound ray incident on the sound receiving point from the temporary sound source;
A building sound simulation system characterized by comprising:   The third computing means is radiated from the temporary sound source to the point of the second reference plane obtained by dividing the inner surface of the transmission space into a plurality of rays, and from the temporary sound source to the sound receiving point. The building sound simulation system according to claim 1, further comprising fourth calculation means for calculating energy of sound rays.   The third calculating means is configured to generate a sound pressure along a path of a sound ray reflected by the second reference plane and reaching the sound receiving point and a sound ray reaching the sound receiving point directly from the temporary sound source. The building sound simulation system according to claim 2, further comprising a fifth calculation unit that calculates a level change.   The second calculating means calculates the energy of the temporary sound source on the transmission space side based on the energy received by the point on the second reference plane calculated by the second calculating means. Item 4. The building sound simulation system according to any one of Items 1 to 3. 5. The building according to claim 1, wherein the first barrier is a virtual barrier that is virtually set, and the sound source space and the transmission space are temporarily separated from each other. Sound simulation system.

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