CN101226235A - Sound source three-dimensional positioning method based on mechanical coupling diaphragm - Google Patents

Abstract

The invention relates to a sound source three-dimension positioning method of sound base mechanical coupling vibration film, belonging to vibration and acoustic technical field. The inventive method comprises 1, using three vibration films mechanically coupled with each other to generate vibration response under sound source actuation, 2, using an energy exchanger and an analogue/digit converter to convert the vibration response into a digit signal, 3, analyzing the digit signal generated in the second step to obtain characteristic quantities relative to the direction of the sound source, 4, using the relationship between the characteristic quantities and the sound source direction, via positioning method to calculate out real-time sound source direction. The invention builds the relationship between the characteristic quantities extracted from the vibration sequence and the sound source direction, to provide a sound source three-dimension positioning method, which resolves the sound source positioning problem of coupling vibration film structure in three-dimension space.

Description

Sound source three-dimensional positioning method based on mechanical coupling diaphragm

Technical field

What the present invention relates to is a kind of vibration and the interior sound localization method of field of acoustics, specifically, is a kind of sound source three-dimensional positioning method based on mechanical coupling diaphragm.

Background technology

Sound localization has significant values in engineering is used, the nineties, people such as American scholar R.N.Miles have studied a kind of Ao Miya palm fibre fly (Ormia ochracea) with excellent acoustic fix ranging ability, and the acoustic fix ranging ability of this tachinid must be easy to the hearing organ that it has coupled structure.In following period of time subsequently, research institutions such as people such as Miles, Tokyo Univ Japan and Univ Maryland-Coll Park USA have proposed corresponding bionical acoustic fix ranging method respectively.But the localization methods that the people proposed such as Yu Miao of people such as Miles and University of Maryland all only have the acoustic bearing function of two dimension, though the acoustic fix ranging method that the scholar of Tokyo University proposes has the three dimensional sound orientating function, but its location theory is perfect inadequately, and orientation error is very big.

Find through literature search prior art, U.S. Patent number 6963653, open day is 2005.11.8, patent name is: multistage directional microphone vibrating diaphragm, this patent readme is: " this invention has microminiaturized feature; be the silicon crystallite microphone diaphragm of a secondary, and this vibrating diaphragm is by the moulding of the little processing and manufacturing technology of silicon." this patent described a kind of pressure reduction type microphone and directional property thereof.But this localization method only possesses the ability of induction to the direction of the sound source on two dimensional surface, and this patent only describes its figure of eight sound source directional property that has, and does not set up perfect localization method.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, propose a kind of sound source three-dimensional positioning method based on mechanical coupling diaphragm, the positioning error that makes its calculated value that can obtain Sounnd source direction information θ and α in three dimensions in real time and the difference between the actual value is less than 2 ° acoustic fix ranging precision.

The present invention is achieved by the following technical solutions, the present invention includes following steps:

The first step adopts three vibrating diaphragms with mutual mechanical couplings, produces vibratory response under the sound source excitation.

In second step, convert the vibratory response that the first step obtains to digital signal by inverting element and analog/digital converter.

In the 3rd step, the digital signal that second step obtained is carried out analyzing and processing, thereby obtain and the information-related characteristic quantity of Sounnd source direction.

The characteristic quantity that described Sounnd source direction is information-related is meant: the predominant frequency f that three vibration signal analyses are obtained ₀, vibration displacement x ₁, x ₃The ratio H of Fourier transform ₁₃With vibration displacement x ₂, x ₃The ratio H of Fourier transform ₂₃, these characteristic quantities are relevant with Sounnd source direction information, wherein x ₁, x ₂And x ₃Be respectively three sequences of vibration displacement signal.

Described Sounnd source direction information is meant the geometric relationship between sound source incident direction and the locating device, also i.e. longitude θ and latitude α in the spherical coordinate system of being determined by locating device, and, can know θ ∈ [0, pi/2] according to the geometric relationship of localization method, α ∈ [0,2 π].

In the 4th step,, adopt localization method to calculate real-time Sounnd source direction information by the one-to-one relationship between characteristic quantity and the Sounnd source direction information.

Described employing localization method calculates real-time Sounnd source direction information, and concrete formula is:

$\left\{\begin{array}{c}\sin \mathrm{\&theta;}=\sqrt{{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}^2}\\ \sin \mathrm{\&alpha;}=\frac{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}{\sqrt{{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}^2}}\\ \cos \mathrm{\&alpha;}=\frac{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}{\sqrt{{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}^2}}\end{array}\right.$

Wherein: $\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1=\frac{\mathrm{cc}}{j\sqrt{3}{\mathrm{\&omega;}}_{0}d}\&CenterDot;\ln \frac{B{H}_{13}+B{H}_{23}+A}{B{H}_{13}+A{H}_{23}+\mathrm{<figure-callout\; id="2"\; label="B\; Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">B</figure-callout>}}& \\ {\mathrm{Index}}_{}{}_2=\frac{\mathrm{cc}}{j3{\mathrm{\&omega;}}_{0}d}\&CenterDot;[\ln \frac{B{H}_{13}+A{H}_{23}+B}{A{H}_{13}+B{H}_{23}+B}+\ln \frac{B{H}_{13}+B{H}_{23}+A}{A{H}_{13}+B{H}_{23}+B}],\end{array}\right.$

$A=\frac{-m{{\mathrm{\&omega;}}_0}^2+j{\mathrm{\&omega;}}_{0}c+{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">k</figure-callout>}}_1+2k_3}{S},$ $B=\frac{k_3}{S}$

In the above-mentioned formula, θ, α are respectively the directional information longitude and the latitude of target sound source, x ₁, x ₂And x ₃Be respectively three sequences of vibration displacement signal, the predominant frequency f of sound source ₀, H ₁₃Be vibration displacement sequence x ₁With x ₃Fourier transform at the ratio at predominant frequency place, H ₂₃Be vibration displacement sequence x ₂With x ₃Fourier transform at the ratio at predominant frequency place, wherein ω ₀=2 π f ₀, j is an imaginary unit, and m is the quality of mechanical coupling diaphragm, and c is the damping of vibrating diaphragm and sound transmission medium, k ₁And k ₃Be respectively the equivalent stiffness of vibrating diaphragm and mechanical couplings structure, S is the area of vibrating diaphragm, these mechanics parameters are determined by the mechanical coupling diaphragm structure, cc is the sound propagation velocity in the medium, it is a known constant, d is the dimensional parameters of coupling diaphragm structure, and the center of representing any single vibrating diaphragm is determined by the mechanical coupling diaphragm structure to the distance between the whole mechanical coupling diaphragm structure centre.

Described localization method, the adequate condition of its establishment is: the frequency of target sound source and the size of structure should satisfy $f_0\&le;\frac{\mathrm{cc}}{4d}$ Perhaps $d\&le;\frac{\mathrm{cc}}{4{\mathrm{<figure-callout\; id="0"\; label="f"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">f</figure-callout>}}_0},$ Wherein cc is the sound propagation velocity in the medium, be a known constant, d is the dimensional parameters of coupling diaphragm structure, and the center of representing any single vibrating diaphragm is to the distance between the whole mechanical coupling diaphragm structure centre, determine the predominant frequency f of sound source by the mechanical coupling diaphragm structure ₀

The present invention has set up the characteristic quantity that extracts from the oscillating sequence relation of source side between information in unison, thereby has obtained a kind of sound source three-dimensional positioning method, has solved the theoretical question of coupled structure auditory localization in the three dimensions.Experiment shows, the present invention is in its frequency range that is suitable for, and positioning error (calculated value of Sounnd source direction information θ and α and the difference between the actual value) is less than 2 °, and will littler (much smaller than 2 °) in the positioning error of low frequency part.

Description of drawings

Fig. 1 is the geometric relationship figure of acoustic fix ranging method.

Fig. 2 is one group of result of Sounnd source direction angle α.

Embodiment

Below in conjunction with accompanying drawing embodiments of the invention are elaborated: present embodiment is being to implement under the prerequisite with the technical solution of the present invention, provided detailed embodiment and concrete operating process, but protection scope of the present invention is not limited to following embodiment.

As shown in Figure 1, the core of present embodiment is the localization method that characteristic quantity obtains Sounnd source direction information in the extraction vibration signal.

Three sequences of vibration displacement signal are respectively x ₁, x ₂And x ₃, utilize autocorrelation function character can determine the predominant frequency f of sound source ₀, the characteristic quantity information-related with Sounnd source direction is H ₁₃, H ₂₃, H wherein ₁₃Be vibration displacement x ₁With vibration displacement x ₃Fourier transform at the ratio at predominant frequency place, in like manner H ₂₃Be vibration displacement x ₂With vibration displacement x ₃Fourier transform at the ratio at predominant frequency place.

Definition:

$A=\frac{-m{{\mathrm{\&omega;}}_0}^2+j{\mathrm{\&omega;}}_{0}c+{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">k</figure-callout>}}_1+2k_3}{S};$ $B=\frac{k_3}{S}$

ω wherein ₀=2 π f ₀J is an imaginary unit; M is the quality of mechanical coupling diaphragm, and c is the damping of vibrating diaphragm and sound transmission medium, k ₁And k ₃Be respectively the equivalent stiffness of vibrating diaphragm and mechanical couplings structure, S is the area of vibrating diaphragm, and these mechanics parameters are determined by the mechanical coupling diaphragm structure, are known quantities to localization method.

Definition again:

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1=\frac{\mathrm{cc}}{j\sqrt{3}{\mathrm{\&omega;}}_{0}d}\&CenterDot;\ln \frac{B{H}_{13}+B{H}_{23}+A}{B{H}_{13}+A{H}_{23}+\mathrm{<figure-callout\; id="2"\; label="B\; Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">B</figure-callout>}}& \\ {\mathrm{Index}}_{}{}_2=\frac{\mathrm{cc}}{j3{\mathrm{\&omega;}}_{0}d}\&CenterDot;[\ln \frac{B{H}_{13}+A{H}_{23}+B}{A{H}_{13}+B{H}_{23}+B}+\ln \frac{B{H}_{13}+B{H}_{23}+A}{A{H}_{13}+B{H}_{23}+B}],\end{array}\right.---\left(1\right)$

Wherein cc is the sound propagation velocity in the medium, is a known constant (for example in air, the velocity of sound under the room temperature is about 344m/s); D is the dimensional parameters of vibrating diaphragm, and the center of representing any single vibrating diaphragm is determined by the mechanical coupling diaphragm structure, as shown in Figure 1 to the distance between the whole mechanical coupling diaphragm structure centre; J, ω ₀, A, B, H ₁₃And H ₂₃Face portion as defined above described.

Can get:

$\left\{\begin{array}{c}\sin \mathrm{\&theta;}=\sqrt{{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}^2}\\ \sin \mathrm{\&alpha;}=\frac{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}{\sqrt{{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}^2}}\\ \cos \mathrm{\&alpha;}=\frac{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}{\sqrt{{{\mathrm{<figure-callout\; id="1"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_1}^2+{{\mathrm{<figure-callout\; id="2"\; label="Index"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">Index</figure-callout>}}_2}^2}}\end{array}\right.---\left(2\right)$

Index wherein ₁, Index ₂Definition as shown in Equation (1).

Can obtain the directional information of sound source by formula (2): longitude θ and latitude α.

Theoretical analysis shows that there is the scope of application in this localization method, and promptly the size of the frequency of its target sound source and structure should satisfy (this condition is the adequate condition that localization method is set up):

${\mathrm{<figure-callout\; id="0"\; label="f"\; filenames="S200810032225XE00011.png"\; state="\{\{state\}\}">f</figure-callout>}}_0\&le;\frac{\mathrm{cc}}{4d}$ Perhaps $d\&le;\frac{\mathrm{cc}}{4f_0}$ (3)

Formula (3) has shown the usage range of this location technology and basic design criteria, wherein cc, d and f ₀Face portion as defined above described.

Present embodiment obtains oscillating sequence by the mechanical model under the sound source incentive action is carried out simulation calculation, by the directional information of above-mentioned localization method calculating sound source, makes comparisons with the Sounnd source direction information of setting arbitrarily in advance in theory.

Present embodiment comprises following each step:

(1) the mechanics emulation by the coupling vibrating diaphragm generates oscillating sequence (i.e. three vibrating diaphragm sound sources excitations produce down and vibrate, the digital signal sequences that obtains by inverting element and analog/digital conversion) x ₁, x ₂And x ₃, default sound source incident angle α=45 °, θ=45 °, the scope that frequency of source calculates is from 0Hz to 25kHz, and in this example, the condition that localization method is set up is f ₀≤ 10kHz;

(2) sequence is handled obtained predominant frequency f ₀, and H ₁₃, H ₂₃

Predominant frequency can utilize the character of the autocorrelation function of each vibration signal x sequence to obtain, and for example establishes x ₁The autocorrelation function of sequence is r _Xx(n), x ₁The sample frequency of sequence is f _s, the autocorrelation function two-phase is faced the N that is spaced apart between the peak value, then:

Predominant frequency $f_{}$ ${}_0=\frac{f_s}{N}$

H ₁₃, H ₂₃Be sequence x as previously mentioned ₁With x ₃Fourier transform at the ratio at predominant frequency place.

(3) calculate the value of θ and α by formula (1), (2);

Can solve sin θ by formula (1) (2), sin α and cos α are according to the geometric relationship of localization method, can know θ ∈ [0, pi/2], α ∈ [0,2 π], so can be according to the sin θ that solves, sin α and cos α value obtain the calculated value of θ and α, and with predefined α=45 °, θ=45 compare then.

(4) calculated value being compared with theoretical value, is example with α, and comparative result as shown in Figure 2.

Result for incident angle α=45 ° shows: have high precision in the zone that present embodiment is suitable for.The factor that precision is exerted an influence mainly is the damping of vibrating diaphragm and sound transmission medium, selects the equivalent damping of vibrating diaphragm and sound transmission medium to be respectively c ₁=6.4 * 10 ^-6Ns/m, c ₂=3.2 * 10 ^-6Ns/m and c ₃=6.4 * 10 ^-7Ns/m, as can be seen: the increase of damping will cause the increase of resultant error, but damping will be very little for the influence of the lower sound incoming signal of dominant frequency, as shown in Figure 2.

This localization method has more accurate station-keeping ability in the zone that its localization method is set up as can be seen, especially is being subjected to damping to influence lower low frequency part, and its locating accuracy is very high.

And in the invalid frequency range of localization method, then can produce mistake, therefore when using present embodiment, at first whether the frequency range of estimating target sound source is positioned within the tolerance band of this localization method.

Present embodiment is by the characteristic quantity setting up oscillating sequence and the extract relation of source side between information in unison, and a kind of sound source three-dimensional positioning method that obtains can obtain very high acoustic fix ranging precision in three dimensions under the situation that localization method is set up.This localization method is in frequency range that it is suitable for, and positioning error (calculated value of Sounnd source direction information θ and α and the difference between the actual value) is less than 2 °, and will littler (much smaller than 2 °) in the positioning error of low frequency part.

Claims (5)

1. the sound source three-dimensional positioning method based on mechanical coupling diaphragm is characterized in that, may further comprise the steps:

The first step adopts three vibrating diaphragms with mutual mechanical couplings, produces vibratory response under the sound source excitation;

In second step, convert the vibratory response that the first step obtains to digital signal by inverting element and analog/digital converter;

In the 3rd step, the digital signal that second step obtained is carried out analyzing and processing, thereby obtain and the information-related characteristic quantity of Sounnd source direction;

In the 4th step,, adopt localization method to calculate real-time Sounnd source direction information by the one-to-one relationship between characteristic quantity and the Sounnd source direction information.

2. the sound source three-dimensional positioning method based on mechanical coupling diaphragm according to claim 1, it is characterized in that, described Sounnd source direction information is meant the geometric relationship between sound source incident direction and the locating device, also i.e. longitude θ and latitude α in the spherical coordinate system of being determined by locating device.

3. the sound source three-dimensional positioning method based on mechanical coupling diaphragm according to claim 1 is characterized in that, the characteristic quantity that described Sounnd source direction is information-related is meant: the predominant frequency f that three vibration signal analyses are obtained ₀, vibration displacement x ₁, x ₃The ratio H of Fourier transform ₁₃With vibration displacement x ₂, x ₃The ratio H of Fourier transform ₂₃, these characteristic quantities are relevant with Sounnd source direction information, wherein x ₁, x ₂And x ₃Be respectively three sequences of vibration displacement signal.

4. the sound source three-dimensional positioning method based on mechanical coupling diaphragm according to claim 1 is characterized in that, described employing localization method calculates real-time Sounnd source direction information, and concrete formula is:

$\left\{\begin{array}{c}\sin \mathrm{\&theta;}=\sqrt{{{\mathrm{Index}}_1}^2+{{\mathrm{Index}}_2}^2}\\ \sin \mathrm{\&alpha;}=\frac{{\mathrm{Index}}_1}{\sqrt{{{\mathrm{Index}}_1}^2+{{\mathrm{Index}}_2}^2}}\\ \cos \mathrm{\&alpha;}=\frac{{\mathrm{Index}}_2}{\sqrt{{{\mathrm{Index}}_1}^2+{{\mathrm{Index}}_2}^2}}\end{array}\right.$

Wherein: $\left\{\begin{array}{c}{\mathrm{Index}}_1=\frac{\mathrm{cc}}{j\sqrt{3}{\mathrm{\&omega;}}_{0}d}\&CenterDot;\ln \frac{B{H}_{13}+B{H}_{23}+A}{B{H}_{13}+A{H}_{23}+B}\\ {\mathrm{Index}}_2=\frac{\mathrm{cc}}{j3{\mathrm{\&omega;}}_{0}d}\&CenterDot;[\ln \frac{B{H}_{13}+A{H}_{23}+B}{A{H}_{13}+B{H}_{23}+B}+\ln \frac{B{H}_{13}+B{H}_{23}+A}{A{H}_{13}+B{H}_{23}+B}],\end{array}\right.$

$A=\frac{-m{{\mathrm{\&omega;}}_0}^2+j{\mathrm{\&omega;}}_{0}c+k_1+2k_3}{S},$ $B=\frac{k_3}{S}$

In the above-mentioned formula, θ, α are respectively the directional information longitude and the latitude of target sound source, x ₁, x ₂And x ₃Be respectively three sequences of vibration displacement signal, the predominant frequency f of sound source ₀, H ₁₃Be vibration displacement sequence x ₁With x ₃Fourier transform at the ratio at predominant frequency place, H ₂₃Be vibration displacement sequence x ₂With x ₃Fourier transform at the ratio at predominant frequency place, wherein ω ₀=2 π f ₀, j is an imaginary unit, and m is the quality of mechanical coupling diaphragm, and c is the damping of vibrating diaphragm and sound transmission medium, k ₁And k ₃Be respectively the equivalent stiffness of vibrating diaphragm and mechanical couplings structure, S is the area of vibrating diaphragm, these mechanics parameters are determined by the mechanical coupling diaphragm structure, cc is the sound propagation velocity in the medium, it is a known constant, d is the dimensional parameters of coupling diaphragm structure, and the center of representing any single vibrating diaphragm is determined by the mechanical coupling diaphragm structure to the distance between the whole mechanical coupling diaphragm structure centre.

5. the sound source three-dimensional positioning method based on mechanical coupling diaphragm according to claim 4 is characterized in that, described localization method, and the adequate condition of its establishment is: the frequency of target sound source and the size of structure should satisfy $f_0\&le;\frac{\mathrm{cc}}{4d}$ Perhaps $d\&le;\frac{\mathrm{cc}}{4f_0},$ Wherein cc is the sound propagation velocity in the medium, be a known constant, d is the dimensional parameters of coupling diaphragm structure, and the center of representing any single vibrating diaphragm is to the distance between the whole mechanical coupling diaphragm structure centre, determine the predominant frequency f of sound source by the mechanical coupling diaphragm structure ₀

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