JP2017153030A - Sound source position estimating apparatus, sound source position estimating method, and sound sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound source position estimating apparatus capable of improving installability of a plurality of microphones.SOLUTION: A sound source position estimating apparatus 100 includes: a sound sensor 10 having a plurality of elements 1 for detecting sounds; a time difference estimating section 32 for estimating a time difference between sounds obtained by a plurality of elements 1; an arithmetic section 33 for calculating a position estimating location of a sound source by calculating from the time difference obtained by the time difference estimating section 32; and a display device 40 for outputting the calculation result of the arithmetic section 33. The plurality of elements 1 is formed on a flexible substrate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sound source position estimation device, a sound source position estimation method, and a sound sensor.

  Patent Document 1 and Patent Document 2 show an example of a technique for estimating a sound source direction and a sound source position using a plurality of microphones. In the technique described in Patent Document 1, the direction of the sound source is determined by detecting the time difference until the sound emitted from the sound source reaches each microphone using a plurality of microphones attached to the casing of the mobile terminal. Calculated. Moreover, in the technique described in Patent Document 2, the time axis of the frequency signal obtained by frequency analysis of the output signal of each microphone is adjusted using a plurality of microphones attached to the bumper of the automobile, The direction of the sound source or the sound source position is calculated based on the result of obtaining the degree of coincidence.

JP 2013-183286 A Japanese Patent No. 4177451

  By the way, when estimating the position of a sound source in a room or the like, it may be a problem how to install a plurality of microphones. In order to estimate the position of the sound source with high accuracy, it is desirable to arrange a plurality of microphones at a certain distance in order to increase the time difference of the sound arrival time from the sound source as much as possible. However, when the microphone is permanently installed in this manner, indoor useability, comfortability, or aesthetics may be impaired. In the techniques described in Patent Document 1 and Patent Document 2, such points are not taken into consideration.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sound source position estimation device, a sound source position estimation method, and a sound sensor that can improve the installation of a plurality of microphones.

  In order to solve the above problems, an aspect of the present invention provides a plurality of sound detection means for detecting sound, a time difference estimation means for estimating a time difference between sounds obtained by the plurality of sound detection means, and the time difference estimation means. And calculating means for calculating the position of the sound source by calculating from the time difference obtained in the step, and output means for outputting the calculation result of the calculating means, wherein the plurality of sound detecting means are configured on a flexible substrate. The sound source position estimation device.

  One embodiment of the present invention is the sound source position estimation device, in which the flexible substrate is integrated with a building material.

  Further, one aspect of the present invention is the above-described sound source position estimation apparatus, further comprising storage means for storing the output from the plurality of sound detection means that is AD (analog-digital) converted.

Further, one aspect of the present invention is the sound source position estimation apparatus, wherein an interval between the plurality of sound detection units is equal to or lower than sound speed × t / 2, where t is the AD conversion interval time.
Further, one aspect of the present invention is the sound source position estimation apparatus, wherein an interval between the plurality of sound detection means is sound speed × t / 2 or more, where t is the AD conversion interval time.

  Further, one aspect of the present invention is the sound source position estimation apparatus, in which the calculation unit has a distance from each sound detection unit of 0.05 w compared to a maximum separation distance w of the plurality of sound detection units. The position estimation location at 10 to 10 w is calculated.

  According to another aspect of the present invention, a sound is detected by a plurality of sound detection units configured on a flexible substrate, a time difference estimation unit estimates a time difference between sounds obtained by the plurality of sound detection units, and a calculation is performed. A sound source position estimation method in which a sound source position estimation place is calculated by calculating from the time difference obtained by the time difference estimation means by means, and a calculation result of the calculation means is output by output means.

  Another embodiment of the present invention is a sound sensor including three or more elements in which a same plane is used as a sound signal receiving surface and an element having a conversion unit that converts vibration received through the receiving surface into an electric signal.

  Another embodiment of the present invention is the above sound sensor, in which the plurality of elements are formed on a flexible base material by coating.

  According to the present invention, it is possible to easily improve the installability of the sound detection means.

It is a block diagram which shows the structural example of the sound source position estimation apparatus which concerns on one Embodiment of this invention. It is a schematic diagram for demonstrating the structural example of the sound sensor 10 shown in FIG. It is a schematic diagram for demonstrating the other structural example of the sound sensor 10 shown in FIG. It is a perspective view which shows typically the structural example of the sound sensor 10 shown in FIG. It is sectional drawing which shows typically the structural example of the sound sensor 10 shown in FIG. It is sectional drawing which shows typically the other structural example of the sound sensor 10 shown in FIG. It is a schematic diagram for demonstrating the operation example of the sound source position estimation apparatus 100 shown in FIG. It is a schematic diagram for demonstrating the operation example of the sound source position estimation apparatus 100 shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a sound source position estimation apparatus 100 according to an embodiment of the present invention. A sound source position estimation device 100 shown in FIG. 1 includes a sound sensor 10, an A / D (analog / digital) conversion device 20, a calculation device 30, and a display device 40 (output means). The sound sensor 10 has a plurality of elements 1 (sound detection means) for detecting sound, and converts the sound detected by each element 1 (hereinafter also referred to as a sound signal) into an electric signal and outputs the electric signal. The A / D converter 20 converts each analog sound signal output as an electrical signal from each element 1 into each digital sound signal and outputs the digital sound signal. The calculation device 30 includes a storage unit 31 (storage unit), a time difference estimation unit 32 (time difference estimation unit), and a calculation unit 33 (calculation unit). The storage unit 31 stores each sound signal obtained by converting the analog sound signal output from each element 1 into a digital signal by the A / D conversion device 20. The time difference estimation unit 32 estimates a time difference between sounds obtained by the plurality of elements 1. The calculation unit 33 calculates the position estimation location of the sound source by calculating from the time difference obtained by the time difference estimation unit 32. The display device 40 displays the calculation results of the calculation unit 33 as images and characters in a predetermined format.

  A configuration example of the sound sensor 10 shown in FIG. 1 will now be described with reference to FIG. In the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The sound sensor 10 shown in FIG. 2 has a sound signal receiving surface 11 as the same plane, and a plurality (3) of elements 1 having a conversion unit (not shown) that converts vibration received through the receiving surface 11 into an electric signal. More) In the example shown in FIG. 2, the sound sensor 10 includes a total of 36 elements 1 in two dimensions, six vertically and horizontally. In the sound sensor 10, each element 1 is configured on a flexible substrate. The receiving surface 11 is the outer surface of the base material of the flexible substrate constituting each element 1 or the outer surface of the protective film (or protective layer) of the flexible substrate. For example, the base material of the flexible substrate is a film made of flexible polyamide or the like, and the protective film (or protective film) or protective layer is also made of polyamide or the like.

  In the example shown in FIG. 2, the flexible substrate constituting each element 1 is integrated with the inner wall 201 of the room 200. However, the flexible substrate constituting each element 1 is not limited to the inner wall 201 but may be integrated with other building materials such as a ceiling, an outer wall, a door, and a window.

  In the example shown in FIG. 2, the plurality of elements 1 are two-dimensionally arranged in a lattice shape. For example, as shown in FIG. 3, each element 1 may be arranged in a single horizontal row. Alternatively, each element 1 may be arranged in a single vertical row.

  Here, with reference to FIGS. 4-6, the structural example of the sound sensor 10 and the element 1 is demonstrated. FIG. 4 is a perspective view schematically showing a configuration example of the sound sensor 10 shown in FIG. The sound sensor 10 shown in FIG. 4 includes a base 14 of a flexible substrate, a beam 13 formed on the base 14 by, for example, coating, and a protective film 12 of the flexible substrate. The inside surrounded by the base material 14, the beam 13, and the protective film 12 is configured as shown in FIG. 5, for example.

  FIG. 5 is a cross-sectional view schematically showing a configuration example of the sound sensor 10 shown in FIG. The base material 14 is bonded to the inner wall 201 so as to be attached and detached through an adhesive layer (not shown). As shown in FIG. 4, the beam 13 is provided not only at the end of the sound sensor 10 but also at the boundary between the elements 1, and the base material 14 and the protective film 12 are separated to form a space 16. In addition, it has a function of separating the space 16 corresponding to each element 1. In this case, the outer surface of the protective film 12 constitutes the sound signal receiving surface 11. The protective film 12 has a plurality of through holes 121. Each element 1 includes a converter 15 that converts vibration received through the receiving surface 11 into an electrical signal. The conversion unit 15 is a component that has a material or a mechanism whose volume or shape changes due to sound, converts the volume or shape change of the material or mechanism into an electrical change, and outputs it. The conversion unit 15 is, for example, a piezoelectric element, and is formed by coating (printing or the like) on a flexible base material. However, the conversion unit 15 is not limited to a piezoelectric element, and may be a capacitor microphone, a microphone using electromagnetic induction, or the like. Each conversion part 15 of each element 1 is arranged at a predetermined interval. The converter 15 receives a wave through the through-hole 121 of the protective film 12 constituting the receiving surface 11 or a wave through the protective film 12 itself through the space 16 and vibrates, and converts the vibration into an electric signal. . Note that the number of through holes 121 may be one or may be omitted.

  FIG. 6 is a cross-sectional view schematically showing another configuration example of the sound sensor 10 shown in FIG. In the configuration example shown in FIG. 6, the protective film 12 is adhered to the inner wall 201 so as to be attached and detached via an adhesive layer (not shown). The outer surface of the base material 14 constitutes a sound signal receiving surface 11. The converter 15 vibrates in response to the wave that has passed through the base material 14 constituting the receiving surface 11 and converts the vibration into an electric signal. The through hole 121a of the protective film 12 may be different in size and number from the through hole 121 shown in FIG. 5 or may be omitted.

  Next, an operation example of the sound source position estimation apparatus 100 shown in FIG. 1 will be described with reference to FIGS. FIG. 7 shows the arrival time of the sound signal from the sound source when the sound signal (not shown) is sufficiently distant from the sound source to a plurality of conversion units 15 (shown as sensors S1 to S4 in FIG. 7). Time differences Δt21 to Δt43 are shown. FIG. 8 shows time differences Δt32 and Δt43 when the sound source SS is in the vicinity and each of the plurality of conversion units 15 (shown as sensors S1 to S4 in FIG. 8) detects a part of the spherical wave. Here, the time difference Δt21 is the time difference between the sensors S1 and S2, the time difference Δt32 is the time difference between the sensors S2 and S3, and the time difference Δt43 is the time difference between the sensors S3 and S4.

  When performing sound source position estimation, the sound source position estimation apparatus 100 first obtains sound signals from a plurality of elements 1, performs A / D conversion by the A / D conversion apparatus 20, and stores the storage unit of the arithmetic apparatus 30. 31. In the arithmetic unit 30, the time difference estimation part 32 calculates | requires a cross correlation by multiplying the digital data between the sensor S1-sensor S2 which sampled, for example, shifting by the sampling corresponding to estimated delay time. The delay time Δt21 between the sensors S1 and S2 is estimated from the delay time equivalent sampling with the highest cross-correlation. At this time, the delay time may be estimated with a phase delay corresponding to the delay time after being converted into frequency components once by FFT (Fast Fourier Transform), DFT (Discrete Fourier Transform), or the like. When there are a plurality of cross correlation peaks, it may be estimated that there are a plurality of sound sources. On the other hand, if the echo is finally from the wall, the sound source may be obtained as a single sound source after solving the simultaneous equations established for each sensor.

  Further, when the sensors S1 to S4 and the like are arranged one-dimensionally in the lateral direction, the position in the plane direction (XY direction) can be estimated. To estimate the XY position, the position of the sound source is set to X and Y, and simultaneous equations are solved from the sensor interval. Further, the closest x and y may be estimated from the genetic method. When x and y of a plurality of sound sources are obtained, a sound pattern may be obtained again by frequency conversion for each sound source to identify whether individuals are different or the same.

  Here, an example of a method for obtaining a time lag between sounds input to the sensors S1 and S2 will be described.

  (1) In the sound source position estimation apparatus 100, first, the sound of the sensor S1 is digitally sampled at 100 kHz (for example, 100,000 points per second) through a 20 kHz analog LPF (low-pass filter).

  (2) Next, the sound of the sensor S2 is digitally sampled at 100 kHz through an analog LPF of 20 kHz (for example, 100,000 points per second).

  (3) Next, the sampling of the sensor S1 is S1-1 to S1-100000, and the sampling of the sensor S2 is S2-1 to S2-100000. Find the cross-correlation at the time of deviation.

  (4) When N in the above equation is changed from −100,000 to 100,000, a peak occurs in the cross-correlation, and the value of N at that time is used as the sound shift time. This peak occurs as many as the number of sound sources.

  Next, a method of position estimation in the calculation unit 33 will be described.

  The position coordinates of the sensors S1, S2,... Are (a1, 0) for the sensor S1, (a2, 0),. Further, the coordinates of the sound source to be calculated are (x, y). The sound speed is Vs. The computing unit 33 can obtain x and y by taking the following simultaneous equations.

  As described above, according to the present embodiment, the installability of the plurality of elements 1 (sound detection means) can be easily improved.

  Note that the sound source position estimation apparatus 100 according to the present embodiment can perform sound source position estimation with high accuracy in the following cases. That is, assuming that the AD conversion interval time is t, the sensor interval (interval of the conversion unit 15 = interval of the element 1) is equal to or less than the sound velocity × t / 2, and the delay time is estimated with a frequency function by Fourier transform. Sometimes desirable. It is desirable that the sensor interval (interval of the conversion unit 15 = interval of the element 1) is equal to or greater than the speed of sound × t / 2 when estimating the delay time on the time axis. Further, it is desirable that the estimated position distance is 0.05 w to 10 w as compared with the maximum separation distance w of the sensor (conversion unit 15 = element 1).

  In the present embodiment, the sound source position is specified using the film type sound sensor array as described above. Further, the position of the sound source is estimated based on the time lag of the electrical signals from the plurality of conversion units 15. Therefore, the designability is high. It is also possible to estimate a sound source that is not a parallel wave near the sensor.

  The embodiment of the present invention is not limited to the above. For example, the sound sensor 10 is not limited to building materials, and may be installed in a moving object or underwater. The receiving surface 11 may be divided into a plurality of parts. Moreover, the receiving surface 11 may face a plurality of different directions. In addition, the A / D conversion device 20, the arithmetic device 30, and the display device 40 may be configured integrally. Further, instead of or in addition to the display device 40, a storage device, a printing device, a communication device, or the like can be used as output means.

DESCRIPTION OF SYMBOLS 100 Sound source position estimation apparatus 1 Element 10 Sound sensor 11 Reception surface 15 Conversion part (Sensor S1, S2, S3, S4)
S1, S2, S3, S4 sensor (conversion unit 15)
20 A / D conversion device 30 Computing device 31 Storage unit 32 Time difference estimating unit 33 Computing unit 40 Display device 201 Inner wall (building material)

Claims (9)

A plurality of sound detection means for detecting sound;
Time difference estimation means for estimating a time difference between sounds obtained by the plurality of sound detection means;
Calculation means for calculating the position estimation location of the sound source by calculating from the time difference obtained by the time difference estimation means,
Output means for outputting the calculation result of the calculation means,
A sound source position estimation apparatus in which the plurality of sound detection means are configured on a flexible substrate. The sound source position estimation apparatus according to claim 1, wherein the flexible substrate is integrated with a building material. The sound source position estimation apparatus according to claim 1, further comprising a storage unit that stores AD (analog-digital) converted outputs from the plurality of sound detection units. The sound source position estimation apparatus according to claim 3, wherein an interval between the plurality of sound detection means is a sound speed × t / 2 or less when the AD conversion interval time is t. The sound source position estimation apparatus according to claim 3, wherein an interval between the plurality of sound detection means is a sound speed × t / 2 or more when the AD conversion interval time is t. The calculation unit calculates the position estimation place where the distance from each sound detection unit is 0.05 w to 10 w as compared with the maximum separation distance w of the plurality of sound detection units. The sound source position estimation apparatus according to claim 1. The sound is detected by a plurality of sound detection means configured on the flexible substrate,
Estimating a time difference between sounds obtained by the plurality of sound detection means by the time difference estimation means;
By calculating from the time difference obtained by the time difference estimating means by the calculating means to calculate the position estimation location of the sound source,
A sound source position estimation method for outputting a calculation result of the calculation means by an output means. A sound sensor comprising three or more elements in which the same plane is used as a sound signal receiving surface, and an element having a conversion unit that converts vibration received through the receiving surface into an electric signal is arranged. The sound sensor according to claim 8, wherein the plurality of elements are formed by coating on a flexible base material.

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