JP7215212B2 - Acoustic property measuring device, acoustic property measuring method, and program - Google Patents

Description

The present invention relates to an acoustic characteristic measuring device, an acoustic characteristic measuring method, and a program for measuring acoustic characteristics of a sound to be measured generated from an object to be measured.

2. Description of the Related Art At a production site, there is a technique for judging the quality of a product based on the sound generated from the product. A large amount of noise is generated around the product to be measured due to the driving of belt conveyors, AGVs (Automated Guided Vehicles), electric drivers, equipment fans, etc., and worker conversations. Since the timing and positions at which these noises occur are not uniform, it is required to exclude noise generated around the measurement object and accurately measure the measurement target sound from the measurement target.

Patent Literature 1 discloses a signal measurement processing device that measures a measurement target sound generated from a measurement target under noise. The device of Patent Document 1 separately collects noise not including the sound to be measured and the sound to be measured mixed with noise, and extracts the sound to be measured by removing the noise from the sound to be measured mixed with noise. .

Japanese Patent Application Laid-Open No. 2002-022530

In the technique of Patent Literature 1, in order to remove noise from the noise-mixed sound to be measured, it is necessary to install a means for collecting noise in the vicinity of the means for collecting the sound to be measured. In the method of Patent Document 1, the sound to be measured is mixed with the noise collected by the means for collecting noise. There was a problem that the sound could not be measured accurately.

SUMMARY OF THE INVENTION An object of the present invention is to provide an acoustic characteristic measuring apparatus for accurately measuring acoustic characteristics of a sound to be measured generated from an object to be measured, in order to solve the above-described problems.

An acoustic characteristic measuring apparatus according to an aspect of the present invention includes a measurement control unit that transmits a control signal to the stage for driving and controlling the movable stage in a state where the positional relationship between the installed measurement object and the microphone is fixed. , a collected sound signal receiving unit that receives the collected sound signal from the microphone, a Fourier transform processing unit that Fourier transforms the collected sound signal received by the collected sound signal receiving unit to generate a frequency spectrum, and a stage movement a measurement signal extraction unit for extracting a measurement signal based on the sound to be measured from the measurement object using a plurality of frequency spectra generated by the Fourier transform processing unit based on the collected sound signal received by the measurement signal extraction unit; and a signal transmitter for transmitting the measurement signal extracted by the unit.

In the acoustic characteristic measurement method according to one aspect of the present invention, the information processing device outputs a control signal for driving and controlling a movable stage in a state in which the positional relationship between the installed measurement object and the microphone is fixed. , receives the collected sound signal from the microphone, Fourier transforms the collected sound signal to generate a frequency spectrum, and generates multiple frequency spectra based on the collected sound signal received as the stage moves. is used to extract a measurement signal based on the sound to be measured from the object to be measured, and the extracted measurement signal is transmitted.

A program according to one aspect of the present invention includes processing for transmitting control signals to the stage for driving and controlling a movable stage in a state in which the positional relationship between an installed measurement object and a microphone is fixed; Measured using multiple frequency spectra generated based on the process of receiving a sound signal, the process of Fourier transforming the collected sound signal to generate a frequency spectrum, and the collected sound signal received as the stage moves. A computer is caused to execute a process of extracting a measurement signal based on the sound to be measured from the object and a process of transmitting the extracted measurement signal.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the acoustic-characteristics measuring device which correctly measures the acoustic characteristic of the sound to be measured which generate|occur|produces from a measuring object.

1 is a conceptual diagram showing an example of the configuration of an acoustic characteristic system according to a first embodiment of the present invention; FIG. It is a block diagram showing an example of composition of an acoustic characteristic measuring device with which an acoustic characteristic system concerning a 1st embodiment of the present invention is provided. FIG. 2 is a conceptual diagram for explaining sound wave measurement by the acoustic property system according to the first embodiment of the present invention; FIG. 2 is a conceptual diagram for explaining sound wave measurement by the acoustic property system according to the first embodiment of the present invention; FIG. 2 is a conceptual diagram for explaining sound wave measurement by the acoustic property system according to the first embodiment of the present invention; FIG. 4 is a conceptual diagram for explaining generation of a bottom hold signal by the acoustic characteristic system according to the first embodiment of the present invention; 4 is a flow chart for explaining the operation of the acoustic characteristic system according to the first embodiment of the present invention; FIG. 4 is a conceptual diagram showing an example of the configuration of an acoustic characteristic system according to a modification of the first embodiment of the present invention; FIG. 6 is a conceptual diagram showing an example of the configuration of an acoustic characteristic system according to a second embodiment of the present invention; FIG. 11 is a conceptual diagram showing an example of the configuration of an acoustic characteristic system according to a modification of the second embodiment of the present invention; FIG. 11 is a conceptual diagram of an acoustic characteristic system according to a modification of the second embodiment of the present invention when viewed obliquely from above; FIG. 11 is a conceptual diagram of another state of the acoustic characteristic system according to the modified example of the second embodiment of the present invention when viewed obliquely from above; FIG. 10 is a block diagram showing an example of the configuration of an acoustic characteristic measuring device included in the acoustic characteristic system according to the second embodiment of the present invention; FIG. 7 is a conceptual diagram for explaining sound wave measurement by the acoustic characteristic system according to the second embodiment of the present invention; FIG. 7 is a conceptual diagram for explaining sound wave measurement by the acoustic characteristic system according to the second embodiment of the present invention; FIG. 7 is a conceptual diagram for explaining sound wave measurement by the acoustic characteristic system according to the second embodiment of the present invention; FIG. 10 is a conceptual diagram for explaining generation of multiplied signals by the acoustic characteristic system according to the second embodiment of the present invention; 8 is a flow chart for explaining the operation of the acoustic characteristic system according to the second embodiment of the present invention; It is a block diagram which shows an example of a structure of the acoustic characteristic measuring device which concerns on the 3rd Embodiment of this invention. It is a block diagram showing an example of hardware constitutions of an acoustic characteristic measuring device concerning each embodiment of the present invention.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, the embodiments described below are technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following. In addition, in all the drawings used for the following description of the embodiments, the same symbols are attached to the same portions unless there is a particular reason. Further, in the following embodiments, repeated descriptions of similar configurations and operations may be omitted. Also, the directions of the arrows in the drawings are only examples, and do not limit the directions of signals between blocks.

(First embodiment)
First, an acoustic characteristic measurement system according to a first embodiment of the present invention will be described with reference to the drawings. The acoustic characteristic measurement system of the present embodiment is used for purposes such as judging the quality of a product based on the measurement target sound generated from the product, which is the measurement target, in a noisy environment such as a production site.

(composition)
FIG. 1 is a conceptual diagram showing an example of the configuration of an acoustic characteristic measurement system 1 of this embodiment. The acoustic property measurement system 1 measures a measurement target sound generated from a measurement target 100 . The acoustic property measurement system 1 includes an acoustic property measurement device 10 , a microphone 110 and a moving stage 120 . In FIG. 1, it is assumed that there is a noise source in the installation environment of the acoustic characteristic measurement system 1 . The noise sources shown in FIG. 1 are merely an example, and the number of noise sources present in the installation environment of the acoustic characteristic measurement system 1 is not limited to one.

The moving stage 120 is a stage for moving the positions of the measuring object 100 and the microphone 110 with respect to the noise source. The measurement object 100 and the microphone 110 are placed on the moving stage 120 with their positional relationship fixed. The moving stage 120 moves according to a control signal from the acoustic property measuring device 10 .

For example, the moving stage 120 is realized by an apparatus having a configuration in which a base portion and a stand installed so as to be movable relative to the base portion are combined. The platform may be configured to move parallel to the horizontal plane, or may be configured to move non-parallel to the horizontal plane. Also, the platform may be configured to move linearly or may be configured to move in a curved line. Also, the moving stage 120 may be installed on a base that rotatably supports the moving stage 120 . Also, the moving stage 120 may be installed on a track that movably supports the moving stage 120 . However, the form of the moving stage 120 is not particularly limited as long as the positional relationship of the microphone 110 with respect to the noise source can be changed while the positional relationship between the measurement object 100 and the microphone 110 is fixed.

For example, the measurement object 100 and the microphone 110 are placed on the upper surface of the moving stage 120 with their positional relationship fixed. Note that the measurement object 100 and the microphone 110 may be arranged on any surface of the moving stage 120 instead of the upper surface of the moving stage 120 with a fixed positional relationship. Further, the measurement object 100 and the microphone 110 may be accommodated inside the moving stage 120 in a state where the positional relationship is fixed.

As the moving stage 120 moves, the measurement object 100 and the microphone 110 change their positional relationship with the noise source while maintaining the same positional relationship. For example, the moving stage 120 is installed on a track that is movably supported. Also, the moving stage 120 may be configured to self-propell so that the positional relationship with the noise source can be changed. However, the method of moving the moving stage 120 is not particularly limited as long as the positional relationship between the measurement object 100, the microphone 110, and the noise source can be changed.

Microphone 110 is arranged on moving stage 120 in a state where the positional relationship with measurement object 100 is fixed. The microphone 110 moves while the positional relationship with the measurement object 100 is fixed as the moving stage 120 moves. The microphone 110 is a sound collecting device that collects the measurement target sound from the measurement target 100 in a state where noise from the noise source is mixed. The microphone 110 converts the collected sound wave into an electric signal (hereinafter referred to as a collected sound signal) and transmits the electric signal to the acoustic characteristic measuring apparatus 10 .

The microphone 110 collects sound waves in which noise from the noise source and sound to be measured from the object to be measured 100 are mixed. Therefore, the level and frequency of the noise from the noise source change as the moving stage 120 moves, but the level and frequency of the sound to be measured from the object to be measured 100 are constant.

Acoustic property measuring apparatus 10 is connected to microphone 110 and moving stage 120 . As the moving stage 120 moves, the distance between the microphone 110 and the moving stage 120 and the acoustic characteristic measuring apparatus 10 changes. Therefore, it is preferable that the microphone 110, the moving stage 120, and the acoustic characteristic measuring apparatus 10 are connected by wire or wirelessly using a deformable cable.

The acoustic characteristic measuring device 10 receives the collected sound signal transmitted by the microphone 110 . The acoustic characteristic measuring device 10 generates a frequency spectrum by Fourier transforming the received collected sound signal, and records the generated frequency spectrum. The acoustic characteristic measuring device 10 uses the collected sound signal from the microphone 110 to generate a plurality of frequency spectra. For example, the acoustic characteristic measuring apparatus 10 continues measurement until the amount of change in the bottom hold signal, which will be described later, reaches a negligible level, or continues measurement for a predetermined time. When stopping the measurement, the acoustic characteristic measuring apparatus 10 transmits a control signal for stopping the moving stage 120 to the moving stage 120 .

The acoustic characteristic measuring apparatus 10 extracts a bottom hold signal having the minimum amplitude for each frequency from the generated frequency spectra. The acoustic characteristic measurement device 10 outputs the extracted bottom hold signal to the measurement control unit 11 and the outside. For example, the bottom hold signal output from the acoustic characteristic measuring device 10 is transmitted to a host system, another system, a display device, or the like.

[Acoustic characteristic measuring device]
Next, a detailed configuration of the acoustic characteristic measuring device 10 will be described with reference to the drawings. FIG. 2 is a block diagram showing an example of the detailed configuration of the acoustic characteristic measuring device 10. As shown in FIG. As shown in FIG. 2 , the acoustic characteristic measurement device 10 includes a measurement control section 11 , a collected sound signal reception section 13 , a Fourier transform processing section 14 , a bottom hold section 15 and a signal transmission section 16 .

The measurement control unit 11 generates a control signal S _c that controls movement of the moving stage 120 . The measurement control unit 11 transmits the generated control signal S _c to the moving stage 120 . At the start of measurement, the measurement control unit 11 transmits a control signal S _c for starting movement of the moving stage 120 . When stopping the measurement, the measurement control unit 11 transmits a control signal S _c to stop the movement of the moving stage 120 . For example, the measurement control unit 11 transmits a control signal S _c for stopping the movement of the moving stage 120 at a predetermined timing. Further, the measurement control section 11 may transmit the control signal S _c for stopping the movement of the moving stage 120 when the amount of change in the bottom hold signal S _BH reaches a negligible level. The timing at which the measurement control unit 11 transmits the control signal S _c for stopping the movement of the moving stage 120 can be set arbitrarily.

The collected sound signal receiving unit 13 receives the collected sound signal S _T from the microphone 110 . The collected sound signal receiving unit 13 outputs the collected sound signal S _T received from the microphone 110 to the Fourier transform processing unit 14 .

The Fourier transform processing unit 14 acquires the collected sound signal S _T from the collected sound signal receiving unit 13 . The Fourier transform processing unit 14 generates a frequency spectrum by Fourier transforming the collected sound signal S _T obtained, and records the generated frequency spectrum. For example, the Fourier transform processing unit 14 generates a frequency spectrum from the collected sound signal _ST by Fast Fourier Transform (FFT), and records the generated frequency spectrum in a recording unit (not shown). The acoustic characteristic measuring device 10 uses the collected sound signal S _T from the microphone 110 to generate a plurality of frequency spectra.

The Fourier transform processing unit 14 outputs the generated multiple frequency spectra to the bottom hold unit 15 . For example, the Fourier transform processing unit 14 outputs a plurality of frequency spectra to the bottom hold unit 15 after generation of all frequency spectra is completed. Further, the Fourier transform processing unit 14 may be configured to output the frequency spectrum to the bottom hold unit 15 each time it generates the frequency spectrum. The timing at which the Fourier transform processing unit 14 outputs the frequency spectrum can be set arbitrarily.

The bottom hold unit 15 acquires multiple frequency spectra from the Fourier transform processing unit 14 . The bottom hold unit 15 extracts the bottom hold signal S _BH having the minimum amplitude for each frequency from a plurality of frequency spectra. The bottom hold section 15 outputs a bottom hold signal S _BH to the signal transmission section 16 and the measurement control section 11 . When the measurement is stopped according to the amount of change in the bottom hold signal S _BH , the bottom hold signal S _BH may be output to the signal transmitting section 16 when the measurement is completed.

The signal transmission section 16 acquires the bottom hold signal S _BH from the bottom hold section 15 . The signal transmission unit 16 outputs the acquired bottom hold signal S _BH . For example, the signal transmitting unit 16 transmits the bottom hold signal S _BH to a host system using the bottom hold signal S _BH (measurement target sound), another system, a display device, or the like.

The above is the description of the configuration of the acoustic characteristic measuring device 10 . The configuration of the acoustic characteristic measuring device 10 of FIG. 2 is an example, and does not limit the configuration of the acoustic characteristic measuring device 10 of this embodiment.

〔Measurement procedure〕
Next, the procedure for measuring the sound to be measured by the acoustic property measurement system 1 will be described with reference to the drawings. 3 to 6 are conceptual diagrams for explaining the measurement procedure of the sound to be measured by the acoustic characteristic measurement system 1. FIG. In this embodiment, the moving stage 120 is assumed to be movably installed on the rails 125 . Although FIGS. 3 to 5 show an example of the frequency spectrum S _f generated at each stage, the frequency spectrum S _f is conceptual, and the frequency spectrum S f at each stage It is not an exact representation of _f .

FIG. 3 shows a state in which the moving stage 120 is stopped at the measurement start position. At the start of measurement, the acoustic characteristic measuring apparatus 10 transmits a control signal S _C1 instructing start of movement to the moving stage 120 at the timing of receiving the collected sound signal S _T1 from the microphone 110 . Upon receiving the control signal S _C1 , the moving stage 120 starts moving according to the control signal S _C1 . The microphone 110 collects a sound wave in which the sound T _M to be measured from the measurement object 100 and the noise T _N1 from the noise source are mixed, and measures the acoustic characteristics of the collected sound signal S _T1 generated from the collected sound wave. Send to device 10 . At this time, the acoustic characteristic measuring device 10 generates the frequency spectrum S _f1 using the received collected sound signal S _T1 . The control signal S _C1 instructing the start of measurement may be configured to be generated by pressing a button by the operator, or may be configured to be automatically generated at a preset measurement time. .

FIG. 4 shows the state of the moving stage 120 in the middle of the measurement. The microphone 110 collects a sound wave in which the sound T _M to be measured from the measurement object 100 and the noise T _N2 from the noise source are mixed, and measures the acoustic characteristics of the collected sound signal S _T2 generated from the collected sound wave. Send to device 10 . At this time, the acoustic characteristic measuring device 10 generates the frequency spectrum S _f2 using the received collected sound signal S _T2 .

FIG. 5 shows a state in which the moving stage 120 has reached the measurement stop position. At the time of stopping the measurement, the acoustic characteristic measuring apparatus 10 transmits the control signal S _Cn instructing to stop moving to the moving stage 120 (n is a natural number of 2 or more) at the timing of reaching the measurement stopping position. When the moving stage 120 receives the control signal S _Cn , it stops moving according to the control signal S _Cn . The microphone 110 collects a sound wave in which the sound T _M to be measured from the measurement object 100 and the noise T _Nn from the noise source are mixed, and measures the acoustic characteristics of the collected sound signal S _Tn generated from the collected sound wave. Send to device 10 . At this time, the acoustic characteristic measuring apparatus 10 receives the collected sound signal S _Tn from the microphone 110 and generates the frequency spectrum S _fn using the received collected sound signal S _Tn .

FIG. 6 is a diagram conceptually showing extraction of the bottom hold signal S _BH from a plurality of frequency spectra S _f generated in each stage of FIGS. 3-5.

The collected sound signal S _T includes the sound to be measured T _M and the noise T _N . Therefore, the frequency spectrum S _f obtained by Fourier transforming the collected sound signal S _T contains the frequency component of the sound T _M to be measured and the frequency component of the noise T _N . Since the positional relationship between the measurement target 100 and the microphone 110 does not change, the frequency spectrum of the measurement target sound T _M included in the frequency spectrum S _f does not change and has a constant frequency and amplitude. On the other hand, the positional relationship between the microphone 110 and the noise source changes as the moving stage 120 moves. The amplitude also changes in proportion to the square. That is, by extracting the bottom hold signal S _BH , which is a signal whose frequency and amplitude do not change, from among a plurality of frequency spectra S _f , it is possible to generate the measurement target sound T _M from which the noise T _N has been removed.

Here, in the environment of the production process, the speed of sound is 345 meters/second, and the distance between the microphone 110 and the noise source is assumed to move away at a speed of 1 meter/second. In this case, the frequency of the sound T _M to be measured included in the frequency spectrum S _f does not change, but the frequency of the noise T _N shifts to the low frequency side by about 3 percent.

It is also assumed that the noise source is located at a distance of 2 meters from the microphone 110 and that the microphone 110 moves away from the noise source by 0.3 meters as the moving stage 120 moves. In this case, the amplitude of the sound T _M to be measured included in the frequency spectrum S _f does not change, but the amplitude of the noise T _N changes by about -2.4 decibels.

The above is the description of the configuration of the acoustic characteristic measurement system 1 of the present embodiment. The configuration shown in FIGS. 1 to 6 is an example, and the configuration of the acoustic characteristic measurement system 1 of this embodiment is not limited to the form as it is.

(motion)
Next, the operation of the acoustic characteristic measuring device 10 of this embodiment will be described with reference to the drawings. FIG. 7 is a flow chart for explaining the operation of the acoustic characteristic measuring device 10. As shown in FIG. In the following description according to the flowchart of FIG. 7, the acoustic characteristic measuring device 10 will be described as the subject of the operation.

In FIG. 7, the acoustic characteristic measuring apparatus 10 first transmits a control signal for starting movement of the moving stage 120 to the moving stage 120 (step S11).

Next, the acoustic characteristic measuring device 10 receives the collected sound signal from the microphone 110 (step S12). It should be noted that reception of the collected sound signal from the microphone 110 may be started before controlling the start of movement of the moving stage 120 .

Next, the acoustic characteristic measuring device 10 Fourier-transforms the collected sound signal to generate a frequency spectrum (step S13).

Next, the acoustic characteristic measuring device 10 records the generated frequency spectrum (step S14).

Here, when stopping the measurement (Yes in step S15), the acoustic characteristic measuring apparatus 10 transmits a control signal for stopping the movement of the moving stage 120 to the moving stage 120 (step S16). On the other hand, if the measurement is to be continued (No in step S15), the process returns to step S12 to continue receiving the collected sound signal.

After step S16, the acoustic characteristic measuring device 10 extracts bottom hold signals from a plurality of frequency spectra (step S17).

Then, the acoustic characteristic measuring device 10 outputs the extracted bottom hold signal as the frequency component of the sound to be measured (step S18).

The above is the description of the operation of the acoustic characteristic measuring device 10 of the present embodiment. The operation of the acoustic characteristic measuring device 10 according to the flowchart of FIG. 7 is an example, and the operation of the acoustic characteristic measuring device 10 of this embodiment is not limited to the procedure as it is.

As described above, the acoustic property measurement system of the present embodiment includes an acoustic property measurement device having a measurement control section, a collected sound signal reception section, a Fourier transform processing section, a bottom hold section, and a signal transmission section. The measurement control unit transmits a control signal to the stage for driving and controlling the movable stage in a state where the positional relationship between the installed measuring object and the microphone is fixed. The collected sound signal receiving unit receives the collected sound signal from the microphone. The Fourier transform processor Fourier transforms the collected sound signal received by the collected sound signal receiver to generate a frequency spectrum. A bottom hold section (also called a measurement signal extraction section) uses a plurality of frequency spectra generated by a Fourier transform processing section based on a collected sound signal received as the stage moves to determine the minimum amplitude for each frequency. to extract the bottom hold signal. A signal transmission part transmits the bottom hold signal which the measurement signal extraction part produced|generated as a measurement signal.

Further, the acoustic characteristic measurement system of this embodiment includes a microphone installed on a moving stage in a state where the positional relationship with the object to be measured is fixed.

Further, the acoustic characteristic measurement system of this embodiment includes a moving stage that moves while the positional relationship between the measurement object and the microphone is fixed. For example, the moving stage is installed on a track that movably supports the moving stage. For example, the moving stage has wheels that movably support the moving stage.

In this embodiment, since the object to be measured and the microphone are moved while the positional relationship between the object to be measured is fixed, the sound to be measured from the object to be measured is collected by the microphone without changing its level or frequency. On the other hand, since the positional relationship between the noise source and the microphone changes, the level and frequency of the noise from the noise source change. Then, by bottom-holding a plurality of frequency spectra generated by Fourier transforming the output signal of the microphone, it is possible to extract the measurement target sound from which noise has been removed.

As described above, according to the present embodiment, even in a production process in which a large number of noise sources exist around an object to be measured, it is possible to easily extract the sound to be measured from which the noise from the noise sources has been removed. It is possible to improve the accuracy of product quality determination.

(Modification)
Here, an acoustic characteristic measurement system of a modified example of the first embodiment of the present invention will be described with reference to the drawings. The acoustic characteristic measurement system of this modification has a stage supported by wheels that can move even if not on the track, instead of the stage that is movably supported on the track. It differs from the configuration of the characteristic measurement system 1 (FIG. 1).

FIG. 8 is a conceptual diagram showing an example of the configuration of the acoustic characteristic measurement system 1-2 of this modified example. The acoustic characteristic measurement system 1-2 measures the sound to be measured generated from the object 100 to be measured. Acoustic property measurement system 1-2 includes acoustic property measurement device 10, microphone 110, and moving stage 120-2. The moving stage 120-2 has wheels 123 for self-running. The acoustic property measurement system 1-2 has the same configuration as the acoustic property measurement system 1 (FIG. 1) of the first embodiment except that it includes a moving stage 120-2 having wheels 123. FIG. Since the operation of the acoustic characteristic measurement system 1-2 of this modified example is the same as that of the acoustic characteristic measurement system 1 of the first embodiment, detailed description thereof will be omitted.

As described above, the moving stage included in the acoustic characteristic measurement system of this modified example has wheels that movably support the moving stage. Note that the moving stage of this modification may be installed on a track that movably supports the moving stage via wheels. According to this modification, the movable stage can be moved without installing a track, so that the system configuration can be simplified and the degree of freedom of the installation location can be improved.

(Second embodiment)
Next, an acoustic characteristic measurement system according to a second embodiment of the present invention will be described with reference to the drawings. The acoustic characteristic measurement system of this embodiment differs from the acoustic characteristic measurement system of the first embodiment in that a multiplied signal is extracted instead of the bottom hold signal. Further, the acoustic characteristic measurement system of this embodiment differs from the acoustic characteristic measurement system of the first embodiment in that a rotating stage is used instead of the moving stage. Note that the moving stage of the first embodiment may be replaced with a rotating stage, or a multiplication signal may be used instead of the bottom hold signal generated in the first embodiment.

(composition)
The acoustic property measurement system 2 measures the measurement target sound generated from the measurement target 200 . The acoustic property measurement system 2 includes an acoustic property measurement device 20 , a microphone 210 and a rotating stage 220 . In FIG. 9, it is assumed that there is a noise source in the installation environment of the acoustic characteristic measurement system 2 . The noise source shown in FIG. 9 is an example, and the number of noise sources present in the installation environment of the acoustic characteristic measurement system 2 is not limited to one.

Rotation stage 220 is a stage for moving the positions of measurement object 200 and microphone 210 with respect to the noise source. The measurement object 200 and the microphone 210 are placed on the rotating stage 220 with their positional relationship fixed. The rotating stage 220 has a rotating mechanism (not shown) and rotates according to a control signal from the acoustic characteristic measuring device 20 .

For example, the rotating stage 220 is implemented by a device having a configuration in which a base portion and a base rotatably installed on the base portion via a rotating mechanism are combined. The platform may be configured to rotate parallel to the horizontal plane, or may be configured to rotate non-parallel to the horizontal plane. Also, the rotation stage 220 may be installed on a track that rotatably supports the rotation stage 220 . However, the form of the rotary stage 220 is not particularly limited as long as the positional relationship of the microphone 210 with respect to the noise source can be changed while the positional relationship between the measurement object 200 and the microphone 210 is fixed. Although FIG. 9 shows a circular rotary stage 220, the shape of the rotary stage 220 is not particularly limited.

For example, the measurement object 200 and the microphone 210 are mounted on the upper surface of the rotating stage 220 with their positional relationship fixed. Note that the measurement object 200 and the microphone 210 may be placed on any surface of the rotation stage 220 instead of the top surface of the rotation stage 220 with a fixed positional relationship. Further, the measurement object 200 and the microphone 210 may be housed inside the rotation stage 220 in a state where the positional relationship is fixed.

In addition, when the surface of the rotating stage 220 is horizontal and the rotating shaft of the rotating stage 220 is perpendicular to the surface, the object to be measured 200 may be arranged on the rotating shaft 221 of the rotating stage 220. . FIG. 10 is a top view of the rotating stage 220 of the acoustic characteristic measurement system 2-1 of the modification. FIGS. 11 and 12 are conceptual diagrams of the rotating stage 220 of the modified acoustic characteristic measuring system 2-1 viewed obliquely from above. 10 to 12, the measurement object 200 is placed on the rotating shaft 221. In the modification shown in FIGS.

10 to 12, the microphone 210 is adjusted so that it is directional with respect to the measurement object 200 or the rotation axis 221. FIG. 12, when the measurement object 200 is not in contact with the rotating stage 220, the measurement object 200 is not rotated, but the positional relationship between the measurement object 200 and the microphone 210 is fixed. Therefore, as long as the sound to be measured from the object to be measured 200 has uniform characteristics with respect to the rotation direction of the rotary stage 220, there is no difference from the measured sound obtained with the configuration shown in FIG.

As the rotary stage 220 rotates, the measurement object 200 and the microphone 210 change their positional relationship with the noise source while maintaining the same positional relationship. For example, the rotary stage 220 rotates so that the positional relationship with the noise source can be changed. However, the method of rotating the rotary stage 220 is not particularly limited as long as the positional relationship between the measurement object 200, the microphone 210, and the noise source can be changed.

Microphone 210 is arranged on rotating stage 220 in a state where the positional relationship with measurement object 200 is fixed. The position of the microphone 210 is changed while the positional relationship with the measurement object 200 is fixed as the rotary stage 220 rotates. The microphone 210 is a sound collecting device that collects the measurement target sound from the measurement target 200 in a state where noise from the noise source is mixed. The microphone 210 converts the collected sound wave into an electric signal (hereinafter referred to as a collected sound signal) and transmits the electric signal to the acoustic characteristic measurement device 20 .

The microphone 210 picks up sound waves in which noise from the noise source and sound to be measured from the object to be measured 200 are mixed. Therefore, the level and frequency of the noise from the noise source change as the rotary stage 220 rotates, but the level and frequency of the sound to be measured from the object to be measured 200 are constant.

However, when the measurement object 200 is not rotating as shown in FIG. 12, the measurement target sound from the measurement object 200 does not have uniform characteristics in the rotation direction of the rotary stage 220 . Therefore, the level of the sound to be measured from the object to be measured 200 is not constant. On the other hand, as will be described later, a unique function of being able to measure the characteristics of the measurement object 200 itself in the direction of rotation is obtained.

Acoustic property measuring device 20 is connected to microphone 210 and rotating stage 220 . As the rotating stage 220 rotates, the distance between the microphone 210 and the rotating stage 220 and the acoustic characteristic measuring device 20 changes. Therefore, it is preferable that the microphone 210, the rotating stage 220, and the acoustic characteristic measuring device 20 are connected by wire or wirelessly with a deformable cable.

Acoustic property measurement device 20 receives collected sound signal S _T transmitted by microphone 210 in accordance with rotation of rotary stage 220 .

Here, regarding the variation in the amplitude of the collected sound signal S _T with respect to the rotation angle of the rotary stage 220, the element caused by the noise source depends approximately in proportion to the sine of the rotation angle. On the other hand, regarding the variation of the amplitude of the collected sound signal S _T with respect to the rotation angle of the rotary stage 220, the factor caused by the measurement object 200 is larger than that caused by the noise source, and is not dependent on the rotation angle at all. Alternatively, it has the characteristic of increasing around a specific rotation angle. Therefore, after measuring the characteristics of the measurement object 200 with respect to the rotation angle from the collected sound signal S _T , preprocessing for equalizing the characteristics in advance may be added.

The acoustic characteristic measuring device 20 generates a frequency spectrum by Fourier transforming the received collected sound signal S _T and records the generated frequency spectrum. The acoustic characteristic measuring device 20 uses the collected sound signal from the microphone 210 to generate a plurality of frequency spectra. For example, the acoustic characteristic measuring device 20 continues measurement until the amount of change in the multiplied signal, which will be described later, reaches a negligible level, or continues measurement for a predetermined period of time. When stopping the measurement, the acoustic characteristic measuring apparatus 20 transmits a control signal for stopping the rotating stage 220 to the rotating stage 220 .

The acoustic characteristic measuring device 20 generates a multiplied signal by multiplying the amplitude of each frequency from the generated multiple frequency spectra. The acoustic characteristic measuring device 20 outputs the generated multiplied signal to the measurement control section 21 and the outside. For example, the multiplied signal output from the acoustic characteristic measuring device 20 is transmitted to a host system, another system, a display device, or the like.

[Acoustic characteristic measuring device]
Next, a detailed configuration of the acoustic characteristic measuring device 20 will be described with reference to the drawings. FIG. 13 is a block diagram showing an example of the detailed configuration of the acoustic characteristic measuring device 20. As shown in FIG. As shown in FIG. 13 , the acoustic characteristic measuring device 20 includes a measurement controller 21 , a collected sound signal receiver 23 , a Fourier transform processor 24 , a multiplier 25 and a signal transmitter 26 .

The measurement control unit 21 generates a control signal S _c that controls rotation of the rotation stage 220 . The measurement control unit 21 transmits the generated control signal S _c to the rotation stage 220 . At the start of measurement, the measurement control unit 21 transmits a control signal S _c for starting rotation of the rotation stage 220 . When stopping the measurement, the measurement control unit 21 transmits a control signal S _c for stopping the rotation of the rotation stage 220 . For example, the measurement control unit 21 transmits a control signal S _c for stopping rotation of the rotation stage 220 at a predetermined timing. Further, the measurement control unit 21 may transmit the control signal S _c for stopping the rotation of the rotation stage 220 when the amount of change in the multiplication signal S _M reaches a negligible level. The timing at which the measurement control unit 21 transmits the control signal S _c for stopping the rotation of the rotation stage 220 can be set arbitrarily.

The collected sound signal receiving unit 23 receives the collected sound signal S _T from the microphone 210 . The collected sound signal receiving unit 23 outputs the collected sound signal S _T received from the microphone 210 to the Fourier transform processing unit 24 .

The Fourier transform processing unit 24 acquires the collected sound signal S _T from the collected sound signal receiving unit 23 . The Fourier transform processing unit 24 generates a frequency spectrum by Fourier transforming the collected sound signal S _T obtained, and records the generated frequency spectrum. For example, the Fourier transform processing unit 24 generates a frequency spectrum from the collected sound signal S _T by Fast Fourier Transform (FFT), and records the generated frequency spectrum in a recording unit (not shown). The acoustic characteristic measuring device 20 uses the collected sound signal S _T from the microphone 210 to generate a plurality of frequency spectra.

The Fourier transform processing unit 24 outputs the generated multiple frequency spectra to the multiplication unit 25 . For example, the Fourier transform processing unit 24 outputs a plurality of frequency spectra to the multiplication unit 25 after generation of all frequency spectra is completed. Moreover, the Fourier transform processing unit 24 may be configured to output the frequency spectrum to the multiplication unit 25 every time it generates the frequency spectrum. The timing at which the Fourier transform processing unit 24 outputs the frequency spectrum can be set arbitrarily.

Multiplication unit 25 acquires a plurality of frequency spectra from Fourier transform processing unit 24 . The multiplier 25 generates a multiplied signal by multiplying the amplitude of each frequency from a plurality of frequency spectra. The multiplier 25 outputs the multiplied signal S _M to the signal transmitter 26 and the measurement controller 21 . In the case of stopping the measurement according to the amount of change in the multiplication signal S _M , the multiplication signal S _M may be output to the signal transmitting section 26 when the measurement is completed.

The signal transmitter 26 acquires the multiplied signal S _M from the multiplier 25 . The signal transmitter 26 outputs the obtained multiplied signal S _M . For example, the signal transmission unit 26 transmits the multiplication signal S _M to a host system using the multiplication signal S _M (sound to be measured), another system, a display device, or the like.

The above is the description of the configuration of the acoustic characteristic measuring device 20 . The configuration of the acoustic characteristic measuring device 20 of FIG. 13 is an example, and does not limit the configuration of the acoustic characteristic measuring device 20 of this embodiment.

〔Measurement procedure〕
Next, the procedure for measuring the sound to be measured by the acoustic property measurement system 2 will be described with reference to the drawings. 14 to 16 are conceptual diagrams for explaining the measurement procedure of the sound to be measured by the acoustic characteristic measurement system 2. FIG. Although FIGS. 14 to 16 show an example of the frequency spectrum S _f generated at each stage, the frequency spectrum S _f is conceptual, and the frequency spectrum S f at each stage It is not an exact representation of _f .

FIG. 14 shows a state in which the rotating stage 220 is stopped at the measurement start position. At the start of measurement, the acoustic characteristic measuring apparatus 20 transmits a control signal S _C1 instructing start of rotation to the rotation stage 220 in synchronization with the timing of receiving the collected sound signal S _T1 from the microphone 210 . Upon receiving the control signal S _C1 , the rotation stage 220 starts rotating according to the control signal S _C1 . The microphone 210 collects a sound wave in which the sound T _M to be measured from the object to be measured 200 and the noise T _N1 from the noise source are mixed, and measures the acoustic characteristics of the collected sound signal S _T1 generated from the collected sound wave. Send to device 20 . At this time, the acoustic characteristic measuring device 20 generates the frequency spectrum S _f1 using the received collected sound signal S _T1 . The control signal S _C1 instructing the start of measurement may be configured to be generated by pressing a button by the operator, or may be configured to be automatically generated at a preset measurement time. .

FIG. 15 shows the state of the rotating stage 220 in the middle of the measurement. The microphone 210 collects a sound wave in which the sound T _M to be measured from the measurement object 200 and the noise T _N2 from the noise source are mixed, and measures the acoustic characteristics of the collected sound signal S _T2 generated from the collected sound wave. Send to device 20 . At this time, the acoustic characteristic measuring device 20 generates the frequency spectrum S _f2 using the received collected sound signal S _T2 .

FIG. 16 shows a state in which the rotating stage 220 has reached the measurement stop position. At the time of stopping the measurement, the acoustic characteristic measuring apparatus 20 transmits a control signal S _Cn instructing to stop rotating to the rotating stage 220 (n is a natural number of 2 or more) in synchronization with the timing of reaching the measurement stopping position. Upon receiving the control signal S _Cn , the rotation stage 220 stops rotating according to the control signal S _Cn . The microphone 210 collects a sound wave in which the sound T _M to be measured from the object to be measured 200 and the noise T _Nn from the noise source are mixed, and measures the acoustic characteristics of the collected sound signal S _Tn generated from the collected sound wave. Send to device 20 . At this time, the acoustic characteristic measuring device 20 receives the collected sound signal S _Tn from the microphone 210 and generates the frequency spectrum S _fn using the received collected sound signal S _Tn .

FIG. 17 is a diagram conceptually showing generation of multiplied signal S _M from a plurality of frequency spectra S _f generated in each stage of FIGS. 14-16.

The collected sound signal S _T includes the sound to be measured T _M and the noise T _N . Therefore, the frequency spectrum S _f obtained by Fourier transforming the collected sound signal S _T contains the frequency component of the sound T _M to be measured and the frequency component of the noise T _N . Since the positional relationship between the measurement object 200 and the microphone 210 does not change, the frequency spectrum of the measurement target sound T _M included in the frequency spectrum S _f does not change and has a constant frequency and amplitude. On the other hand, the positional relationship between the microphone 210 and the noise source changes as the rotary stage 220 rotates. The amplitude also changes in proportion to the square. That is, by extracting the multiplication signal _SM , which is a signal whose frequency and amplitude do not change, from a plurality of frequency spectra _Sf , it is possible to generate the measurement target sound T _M from which the noise T _N has been removed.

The above is the description of the configuration of the acoustic characteristic measurement system 2 of the present embodiment. The configurations shown in FIGS. 9 to 16 are examples, and the configuration of the acoustic characteristic measurement system 2 of this embodiment is not limited to the form as it is.

(motion)
Next, the operation of the acoustic characteristic measuring device 20 of this embodiment will be described with reference to the drawings. FIG. 18 is a flow chart for explaining the operation of the acoustic characteristic measuring device 20. As shown in FIG. In the following description according to the flowchart of FIG. 18, the acoustic characteristic measuring device 20 will be described as the subject of the operation.

In FIG. 18, the acoustic characteristic measuring device 20 first transmits a control signal for starting rotation of the rotating stage 220 to the rotating stage 220 (step S21).

Next, the acoustic characteristic measuring device 20 receives the collected sound signal from the microphone 210 (step S22). It should be noted that reception of the collected sound signal from the microphone 210 may be started before controlling the start of rotation of the rotary stage 220 .

Next, the acoustic characteristic measuring device 20 Fourier-transforms the collected sound signal to generate a frequency spectrum (step S23).

Next, the acoustic characteristic measuring device 20 records the generated frequency spectrum (step S24).

Here, when stopping the measurement (Yes in step S25), the acoustic characteristic measuring apparatus 20 transmits a control signal for stopping the rotation of the rotating stage 220 to the rotating stage 220 (step S26). On the other hand, if the measurement is to be continued (No in step S25), the process returns to step S22 to continue receiving the collected sound signal.

After step S26, the acoustic characteristic measuring device 20 generates a multiplied signal from a plurality of frequency spectra (step S27).

Then, the acoustic characteristic measuring device 20 outputs the generated multiplied signal as the frequency component of the sound to be measured (step S28).

The above is the description of the operation of the acoustic characteristic measuring device 20 of the present embodiment. The operation of the acoustic characteristic measuring device 20 according to the flowchart of FIG. 18 is an example, and the operation of the acoustic characteristic measuring device 20 of this embodiment is not limited to the procedure as it is.

As described above, the acoustic characteristic measuring apparatus of the present embodiment includes a measurement controller, a collected sound signal receiver, a Fourier transform processor, a multiplier, and a signal transmitter. The measurement control unit transmits to the stage a control signal for driving and controlling the rotatable stage in a state where the positional relationship between the installed measuring object and the microphone is fixed. The collected sound signal receiving unit receives the collected sound signal from the microphone. The Fourier transform processor Fourier transforms the collected sound signal received by the collected sound signal receiver to generate a frequency spectrum. A multiplication unit (also called a measurement signal extraction unit) multiplies the amplitude of each frequency using a plurality of frequency spectra generated by the Fourier transform processing unit based on the collected sound signal received as the stage moves. Generate a signal. A signal transmission part transmits the multiplication signal which the measurement signal extraction part produced|generated as a measurement signal.

Further, the acoustic characteristic measurement system of the present embodiment has a rotation mechanism that rotates the measurement object and the microphone while their positional relationship is fixed.

In this embodiment, since the object to be measured and the microphone are rotated while the positional relationship between the object to be measured is fixed, the sound to be measured from the object to be measured is collected by the microphone without changing its level or frequency. On the other hand, since the positional relationship between the noise source and the microphone changes, the level and frequency of the noise from the noise source change. Then, by multiplying a plurality of frequency spectra generated by Fourier transforming the output signal of the microphone, it is possible to extract the sound to be measured from which noise has been removed.

As described above, according to the present embodiment, even in a production process in which a large number of noise sources exist around an object to be measured, it is possible to easily extract the sound to be measured from which the noise from the noise sources has been removed. It is possible to improve the accuracy of product quality determination.

(Third embodiment)
Next, an acoustic characteristic measuring device according to a third embodiment of the present invention will be described with reference to the drawings. The acoustic property measuring device of the present embodiment is a generic concept of the acoustic property measuring devices included in the acoustic property measuring systems according to the first and second embodiments. A configuration obtained by adding at least one of a stage and a microphone to the acoustic characteristic measuring apparatus of this embodiment may be called an acoustic characteristic measuring apparatus.

As shown in FIG. 19, the acoustic characteristic measuring device 30 of this embodiment includes a measurement control unit 31, a collected sound signal reception unit 33, a Fourier transform processing unit 34, a measurement signal extraction unit 35, and a signal transmission unit . Acoustic characteristic measuring device 30 receives a collected sound signal S _T from a microphone (not shown) installed on a stage capable of changing the positional relationship from the noise source, and generates a control signal for driving and controlling the stage on which the microphone is installed. to the stage. However, it is assumed that the positional relationship between the microphone and the object to be measured is fixed when placed on the stage.

The measurement control unit 31 generates a control signal S _c that controls driving of the stage. The measurement control unit 31 transmits the generated control signal S _c to the stage. For example, the stage moves or rotates according to the control signal S _c from the measurement control section 31 . At the start of measurement, the measurement control unit 31 transmits a control signal S _c for starting driving of the stage. At the time of stopping the measurement, the measurement control unit 31 transmits a control signal S _c for stopping the driving of the stage. For example, the measurement control unit 31 transmits a control signal _Sc to stop driving the stage at a predetermined timing. Further, the measurement control section 31 may transmit the control signal S _c for stopping the movement of the stage when the amount of change in the measurement signal S _OUT reaches a negligible level. The timing at which the measurement control unit 31 transmits the control signal S _c for stopping the driving of the stage can be set arbitrarily.

The collected sound signal receiving unit 33 receives the collected sound signal S _T from the microphone. The collected sound signal receiving unit 33 outputs the collected sound signal S _T received from the microphone to the Fourier transform processing unit 34 .

The Fourier transform processing unit 34 acquires the collected sound signal S _T from the collected sound signal receiving unit 33 . The Fourier transform processing unit 34 generates a frequency spectrum by Fourier transforming the collected sound signal S _T obtained, and records the generated frequency spectrum. For example, the Fourier transform processing unit 34 generates a frequency spectrum from the collected sound signal _ST by Fast Fourier Transform (FFT), and records the generated frequency spectrum in a recording unit (not shown). The acoustic characteristic measuring device 30 generates a plurality of frequency spectra using the collected sound signal S _T from the microphone.

The Fourier transform processor 34 outputs the generated multiple frequency spectra to the measurement signal extractor 35 . For example, the Fourier transform processing unit 34 outputs a plurality of frequency spectra to the measurement signal extraction unit 35 after generation of all frequency spectra is completed. Further, the Fourier transform processing unit 34 may be configured to output the frequency spectrum to the measurement signal extraction unit 35 each time it generates the frequency spectrum. The timing at which the Fourier transform processing unit 34 outputs the frequency spectrum can be set arbitrarily.

The measurement signal extractor 35 acquires a plurality of frequency spectra from the Fourier transform processor 34 . The measurement signal extractor 35 generates the measurement signal S _OUT using a plurality of frequency spectra. For example, the measurement signal extraction unit 35 generates, as the measurement signal S _OUT , a bottom hold signal with the minimum amplitude for each frequency from a plurality of frequency spectra. Also, for example, the measurement signal extraction unit 35 generates a multiplication signal obtained by multiplying the amplitude of each frequency from a plurality of frequency spectra as the measurement signal S _OUT . The measurement signal extraction section 35 outputs the measurement signal S _OUT to the signal transmission section 36 and the measurement control section 31 . If the measurement is stopped according to the amount of change in the measurement signal S _OUT , the measurement signal S _OUT may be output to the signal transmission section 36 when the measurement is completed.

The signal transmission section 36 acquires the measurement signal S _OUT from the measurement signal extraction section 35 . The signal transmitter 36 outputs the acquired measurement signal S _OUT . For example, the signal transmission unit 36 transmits the measurement signal S _OUT to a host system using the measurement signal S _OUT or another system.

The above is the description of the configuration of the acoustic characteristic measuring device 30 . The configuration of the acoustic characteristic measuring device 30 of FIG. 19 is an example, and does not limit the configuration of the acoustic characteristic measuring device 30 of this embodiment.

As described above, the acoustic characteristic measuring apparatus of this embodiment includes a measurement control section, a collected sound signal receiving section, a Fourier transform processing section, a measurement signal extracting section, and a signal transmitting section. The measurement control unit transmits a control signal to the stage for driving and controlling the movable stage in a state where the positional relationship between the installed measuring object and the microphone is fixed. The collected sound signal receiving unit receives the collected sound signal from the microphone. The Fourier transform processor Fourier transforms the collected sound signal received by the collected sound signal receiver to generate a frequency spectrum. The measurement signal extraction unit extracts a measurement signal based on the sound to be measured from the object using a plurality of frequency spectra generated by the Fourier transform processing unit based on the collected sound signals received as the stage moves. Extract. The signal transmission section transmits the measurement signal extracted by the measurement signal extraction section.

According to the acoustic characteristic measuring apparatus of the present embodiment, it is possible to accurately measure the acoustic characteristic of the sound to be measured generated from the object to be measured.

(hardware)
Here, the hardware configuration for executing the processing of the acoustic characteristic measuring device according to each embodiment of the present invention will be described by taking the information processing device 90 in FIG. 20 as an example. Note that the information processing device 90 of FIG. 20 is a configuration example for executing processing of the acoustic characteristic measuring device of each embodiment, and does not limit the scope of the present invention.

As shown in FIG. 20, an information processing device 90 includes a processor 91 , a main memory device 92 , an auxiliary memory device 93 , an input/output interface 95 and a communication interface 96 . In FIG. 20, the interface is abbreviated as I/F (Interface). Processor 91 , main storage device 92 , auxiliary storage device 93 , input/output interface 95 , and communication interface 96 are connected to each other via bus 99 so as to enable data communication. Also, the processor 91 , the main storage device 92 , the auxiliary storage device 93 and the input/output interface 95 are connected to a network such as the Internet or an intranet via a communication interface 96 .

The processor 91 expands a program stored in the auxiliary storage device 93 or the like into the main storage device 92 and executes the expanded program. In this embodiment, a configuration using a software program installed in the information processing device 90 may be used. The processor 91 executes processing by the acoustic characteristic measuring device according to this embodiment.

The main memory 92 has an area in which programs are expanded. The main memory device 92 may be a volatile memory such as a DRAM (Dynamic Random Access Memory). Also, a non-volatile memory such as MRAM (Magnetoresistive Random Access Memory) may be configured and added as the main storage device 92 .

The auxiliary storage device 93 stores various data. The auxiliary storage device 93 is configured by a local disk such as a hard disk or flash memory. It should be noted that it is possible to store various data in the main storage device 92 and omit the auxiliary storage device 93 .

The input/output interface 95 is an interface for connecting the information processing device 90 and peripheral devices. A communication interface 96 is an interface for connecting to an external system or device through a network such as the Internet or an intranet based on standards and specifications. The input/output interface 95 and the communication interface 96 may be shared as an interface for connecting with external devices.

The information processing apparatus 90 may be configured to connect input devices such as a keyboard, mouse, and touch panel as necessary. These input devices are used to enter information and settings. Note that when a touch panel is used as an input device, the display screen of the display device may also serve as an interface of the input device. Data communication between the processor 91 and the input device may be mediated by the input/output interface 95 .

Further, the information processing device 90 may be equipped with a display device for displaying information. When a display device is provided, the information processing device 90 is preferably provided with a display control device (not shown) for controlling the display of the display device. The display device may be connected to the information processing device 90 via the input/output interface 95 .

Further, the information processing device 90 may be equipped with a disk drive, if necessary. Disk drives are connected to bus 99 . Between the processor 91 and a recording medium (program recording medium) not shown, the disk drive mediates reading of data programs from the recording medium and writing of processing results of the information processing device 90 to the recording medium. The recording medium can be implemented by, for example, an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). The recording medium may be a semiconductor recording medium such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) card, a magnetic recording medium such as a flexible disk, or other recording medium.

The above is an example of the hardware configuration for enabling the acoustic characteristic measuring device according to each embodiment of the present invention. Note that the hardware configuration of FIG. 20 is an example of the hardware configuration for executing arithmetic processing of the acoustic characteristic measuring device according to each embodiment, and does not limit the scope of the present invention. The scope of the present invention also includes a program that causes a computer to execute processing related to the acoustic characteristic measuring apparatus according to each embodiment. Further, the scope of the present invention also includes a program recording medium on which the program according to each embodiment is recorded.

The components of the acoustic characteristic measuring device of each embodiment can be combined arbitrarily. Also, the constituent elements of the acoustic characteristic measuring apparatus of each embodiment may be realized by software or by circuits.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

1, 2 acoustic property measurement system 10, 20, 30 acoustic property measurement device 11, 21, 31 measurement control unit 13, 23, 33 collected sound signal reception unit 14, 24, 34 Fourier transform processing unit 15 bottom hold unit 16 signal transmission Section 25 Multiplication Section 26 Signal Transmission Section 35 Measurement Signal Extraction Section 36 Signal Transmission Section 110, 210 Microphone 120 Movement Stage 220 Rotation Stage

Claims (10)

measurement control means for transmitting a control signal to the stage for driving and controlling a movable stage in a state where the positional relationship between the installed measurement object and the microphone is fixed;
a collected sound signal receiving means for receiving a collected sound signal from the microphone;
Fourier transform means for Fourier transforming the collected sound signal received by the collected sound signal receiving means to generate a frequency spectrum;
extracting a measurement signal based on the sound to be measured from the object to be measured using the plurality of frequency spectra generated by the Fourier transform means based on the collected sound signal received along with the movement of the stage; measurement signal extraction means;
and a signal transmission means for transmitting the measurement signal extracted by the measurement signal extraction means. The measurement signal extraction means is
extracting a bottom hold signal with the smallest amplitude for each frequency from the plurality of frequency spectra;
The signal transmission means is
2. The acoustic characteristic measuring apparatus according to claim 1, wherein said bottom hold signal extracted by said measurement signal extracting means is transmitted as said measurement signal. The measurement signal extraction means is
generating a multiplied signal obtained by multiplying the amplitude of each frequency from the plurality of frequency spectra;
The signal transmission means is
2. The acoustic characteristic measuring apparatus according to claim 1, wherein said multiplied signal generated by said measurement signal extracting means is transmitted as said measurement signal. 4. The acoustic characteristic measuring apparatus according to any one of claims 1 to 3, comprising the microphone installed on the stage in a state where the positional relationship with the object to be measured is fixed. 5. The acoustic characteristic measurement according to any one of claims 1 to 4, further comprising the stage capable of moving in a state in which the positional relationship between the installed measurement object and the microphone is fixed according to the control signal. Device. The stage is
6. The acoustic characteristic measuring apparatus according to claim 5, which is installed on a track that movably supports said stage, and has wheels for moving on said track. The stage is
7. The acoustic characteristic measurement apparatus according to claim 5, further comprising a rotation mechanism capable of rotating the installed object to be measured and the microphone in a fixed positional relationship. The microphone is
8. The acoustic characteristic measuring apparatus according to claim 7, wherein the positional relationship with the object to be measured is fixed, and the apparatus is on the rotation axis of the rotating mechanism. The information processing device
transmitting a control signal to the stage for driving and controlling a movable stage in a state where the positional relationship between the installed measurement object and the microphone is fixed;
receiving a collected sound signal from the microphone;
Fourier transforming the collected sound signal to generate a frequency spectrum,
extracting a measurement signal based on the sound to be measured from the object using the plurality of frequency spectra generated based on the collected sound signal received as the stage moves;
An acoustic characteristic measuring method for transmitting the extracted measurement signal. A process of transmitting a control signal to the stage for driving and controlling a movable stage in a state where the positional relationship between the installed measurement object and the microphone is fixed;
a process of receiving a collected sound signal from the microphone;
a process of Fourier transforming the collected sound signal to generate a frequency spectrum;
A process of extracting a measurement signal based on the sound to be measured from the object using the plurality of frequency spectra generated based on the collected sound signal received as the stage moves;
A program for causing a computer to execute a process of transmitting the extracted measurement signal.

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