CN103439689B - Microphone position estimating system in a kind of distributed mike wind array - Google Patents

Abstract

The invention discloses microphone position estimating system in a kind of distributed mike wind array, comprise sound-source signal generation module, loudspeaker, reference microphone, microphone to be positioned and microphone position estimation module; Sound-source signal generation module output terminal output signal is converted to sound through loudspeaker and plays in the work-yard of distributed mike wind array; The referenced microphone of this sound and microphone to be positioned received; The signal of reference microphone and microphones to be positioned is passed to the microphone position estimation module corresponding with microphone to be positioned simultaneously.The present invention's signal of three different frequency bands audible signal as three sound sources, disposable collection in microphone position estimation procedure also isolates three sound sources, can realize the On-line Estimation of microphone position.Distance-finding method based on energy and time delay is combined by the present invention, successively carries out rough, the fine estimation of distance, ensure that location estimation has less calculated amount and higher precision.

Description

Microphone position estimating system in a kind of distributed mike wind array

Technical field

The present invention relates to a kind of location estimation technology of microphone array, particularly microphone position estimating system in a kind of distributed mike wind array.

Background technology

Microphone array is rearranged by multiple microphone, the collection signal while of each microphone also carries out Combined Treatment to signal, not only can effectively restraint speckle and reverberation, obtain good tonequality, the azimuth information of sound can also be obtained, play an important role so microphone array is listed in the application such as speech enhan-cement, auditory localization, Sound seperation.In recent years, along with the development of the progress of integrated circuit technique and network service, mobile calculation technique, emerge a collection of portable equipment (as notebook computer, smart mobile phone etc.) being usually furnished with Wi-Fi, bluetooth, audio interface etc., and constantly popularization and application in routine work life.Utilize these portable equipments, adhoc distributed mike wind array can be formed.

Different from regular microphone array, distributed mike array does not have the information such as predetermined geometry and size, and each microphone may be controlled by processor alone, independent acquisition and process data.Because the information such as geometry, size of distributed mike wind array cannot be predicted, and carry out distributed mike wind Array Signal Processing and need these information, therefore, how to determine that the microphone position in distributed mike wind array is a technical barrier that must solve.

Chen Di equal within 2011, at publication number be CN102123495A patent in disclose " a kind of wireless sensor network centroid localization algorithm corrected based on RSSI ".The RSSI ranging technology of the method by correcting, the distance of point-to-point between measured node, adopts triangle centroid algorithm to carry out node locating afterwards.The method calculated amount is little, is easy to realize, and has good practical value.But for distributed mike wind array, because voice signal power changes in time, and big rise and fall, so adopt signal energy to find range, precision is often not high enough.

The correction sound source of three diverse locations is adopted to carry out microphone position in correction microphone array in " the bearing calibration research of microphone array " that Chengdu University of Electronic Science and Technology Xiao Hua delivered in 2008.A sound source is successively positioned over three positions by the program, divides collection and the calculating of carrying out signal for three times, finally three result of calculations is merged and obtains microphone position.But the operation of the signals collecting of the method is more loaded down with trivial details, and efficiency is lower, can only calculated off-line, cannot realize the On-line Estimation of microphone position.

Summary of the invention

For solving the problems referred to above that prior art exists, the present invention will design a kind ofly not only to have been had degree of precision, but also has less computation complexity and can realize microphone position estimating system in the distributed mike wind array of On-line Estimation.

To achieve these goals, technical scheme of the present invention is as follows: microphone position estimating system in a kind of distributed mike wind array, comprises sound-source signal generation module, loudspeaker, reference microphone, multiple microphone to be positioned and multiple microphone position estimation module; Described sound-source signal generation module output terminal output signal is converted to sound through loudspeaker and plays in the work-yard of distributed mike wind array; The referenced microphone of this sound and microphone to be positioned received; The signal of reference microphone and microphones to be positioned is passed to the microphone position estimation module corresponding with microphone to be positioned simultaneously; The output terminal of described microphone position estimation module exports the coordinate of microphone to be positioned; Described microphone to be positioned and microphone position estimation module one_to_one corresponding;

The method of work of described sound-source signal generation module comprises the following steps:

Described sound-source signal generation module comprises white noise generator and bandpass filter, white noise generator produces white noise signal, described white noise signal passes through the different bandpass filter of three passbands, produce the bandpass signal of three different frequency bands, as the audible signal of three sound sources, input is placed in 3, distributed mike wind array operation place loudspeaker respectively; If the unit impulse response of three bandpass filter is respectively h _jn (), j=1,2,3, carries out filtering to white noise signal x (n) that white noise generator produces respectively, obtains the bandpass signal s of three different frequency bands _j(n), j=1,2,3,

s _j(n)＝x(n)*h _j(n)，j＝1、2、3

Wherein, the convolution algorithm in symbol " * " representative digit signal transacting field; N represents signal x, unit impulse response h ₁, h ₂, h ₃the sequence number of each sampled value;

Described microphone position estimation module quantity is identical with the quantity of microphone to be positioned, and the working method method of each microphone position estimation module is identical; If i-th microphone position estimation module corresponds to i-th microphone to be positioned, this module comprise signal validation checking submodule, reference microphone sound-source signal segregant module, reference microphone sub-band ground unrest estimator module, microphone sound-source signal segregant module to be positioned, microphone sub-band ground unrest estimator module to be positioned, distance rough estimate submodule, apart from smart estimator module and triangle centroid calculation submodule;

Whether described signal validation checking submodule detects input signal effective, and the signal s that computing reference microphones arrives _rthe short-time energy E of (n) every frame _r

$E_r=\underset{n=\mathrm{start}}{\overset{\mathrm{start}+M-1}{\mathrm{\Σ}}}{s}_r^2\left(n\right)$

Wherein, M represents frame length, and start represents that present frame is at original received signal sequence s _rreference position in (n); Relatively E _rwith signal/noise decision threshold E _thrif, E _r<E _thr, judge that present frame is as noise frame, otherwise, judge that present frame is as signal frame;

When judging present frame as noise frame, estimating background noise comprising ENERGY E _min, upgrade availability deciding threshold value E _thr; This threshold value update method is

ifE _min＜E _r

E _min＝E _r

E _thr＝aE _min

endif

Wherein, a is a constant, and the span of a is 1<a<100;

Described reference microphone sound-source signal segregant module utilizes three bandpass filter identical with coefficient in sound-source signal generation module to be separated by three sound-source signals; The unit impulse response of these three bandpass filter is also h _jn (), j=1,2,3, to reference microphone Received signal strength s _rn () carries out filtering respectively, obtain the signal s of three different frequency bands _rj(n), j=1,2,3, namely

s _rj(n)=s _r(n)*h _j(n)，j=1、2、3

When judging present frame as noise frame, described reference microphone sub-band ground unrest estimator module estimates the ENERGY E of three sub-bands respectively _rj, j=1,2,3,

$E_{\mathrm{rj}}=\underset{n=\mathrm{start}}{\overset{\mathrm{start}+M-1}{\mathrm{\&Sigma;}}}{s}_{\mathrm{rj}}^2\left(n\right),$ j=1、2、3

By E _rj, j=1,2,3, with a front reference microphone sub-band background noise energy estimated result ε _{rj, old}smoothing, sharpening result is as current background noise energy estimated value ε _{rj, curr},

ε _rj，curr＝(1-b)·ε _rj，old+b·E _rj，j＝1、2、3

Wherein, b is smoothing factor, represents present energy E _rj, j=1,2,3, proportion when level and smooth, the span of b is 0<b<1;

Described microphone sound-source signal segregant module to be positioned utilizes three bandpass filter identical with coefficient in sound-source signal generation module to be separated by three sound-source signals; The unit impulse response of these three bandpass filter is also h _jn (), j=1,2,3, to microphones signal s to be positioned _in () carries out filtering respectively, obtain the signal of three different frequency bands, namely

s _ij(n)=s _i(n)*h _j(n)，j=1、2、3

When judging present frame as noise frame, described microphone sub-band ground unrest estimator module to be positioned estimates the ENERGY E of three sub-bands respectively _ij, j=1,2,3,

$E_{\mathrm{ij}}=\underset{n=\mathrm{start}}{\overset{\mathrm{start}+M-1}{\mathrm{\&Sigma;}}}{s}_{\mathrm{ij}}^2\left(n\right),$ j=1、2、3

Again by E _ij, j=1,2,3, with front once microphone sub-band background noise energy estimated result ε to be positioned _{ij, old}smoothing, sharpening result is as current background noise energy estimated value ε _{ij, curr},

ε _ij，curr＝(1-b)·ε _ij，old+b·E _ij，j＝1、2、3

Wherein, b is smoothing factor, represents present energy E _ij, j=1,2,3, proportion when level and smooth, the span of b is 0<b<1;

The described distance rough estimate submodule course of work is as follows:

Definition footmark r represents reference microphone, and footmark i represents i-th microphone to be positioned, and footmark j represents a jth sound source (i.e. a jth loudspeaker, j=1,2,3), d _ijrepresent the Euclidean distance between a jth sound source and i-th microphone to be positioned, (x _r, y _r) and (x _j, y _j) represent the coordinate of reference microphone and a jth sound source, d respectively _rjrepresent the Euclidean distance of jth between sound source and reference microphone when microphone gain calibrates (the microphone output signal energy namely under the identical sound intensity is identical), when judging present frame as signal frame, then i-th microphone to be positioned is to the distance rough estimate of a jth sound source for

${\tilde{d}}_{\mathrm{ij}}=d_{\mathrm{rj}}\&CenterDot;\sqrt{\frac{E_{\mathrm{rj}}\left(t\right){-\mathrm{\&epsiv;}}_{\mathrm{rj}}\left(t\right)}{E_{\mathrm{ij}}\left(t\right)-{\mathrm{\&epsiv;}}_{\mathrm{ij}}\left(t\right)}},$ j=1、2、3

For improving the accuracy that follow-up distance essence is estimated, by current distance rough estimate result j=1,2,3, with previous sharpening result di _{j, old}smoothing, obtain current distance rough estimate sharpening result d _{ij, curr}

$d_{\mathrm{ij},\mathrm{curr}}=(1-\mathrm{\&beta;})\&CenterDot;d_{\mathrm{ij},\mathrm{old}}+\mathrm{\&beta;}\&CenterDot;{\tilde{d}}_{\mathrm{ij}},$ j=1、2、3

Wherein, β is smoothing factor, represents current distance rough estimate result proportion in smoothing process, the span of β is 0< β <1;

Described distance essence estimator module routine is as follows:

Definition α _rjand α _ijbe respectively sound propagates into reference microphone and i-th microphone to be positioned decay factor from sound source j, τ _rjand τ _ijbe respectively sound propagates into reference microphone and i-th microphone to be positioned time delay from sound source j, v _r(n) and v _in () is respectively the ground unrest at reference microphone and i-th microphone place to be positioned, when judging present frame as signal frame, reference microphone and i-th microphones to be positioned to come from same sound source s _isignal be respectively

$\begin{array}{c}{s}_{\mathrm{rj}}\left(n\right)={\mathrm{\&alpha;}}_{\mathrm{rj}}{s}_j(n-{\mathrm{\&tau;}}_{\mathrm{rj}})+v_r\left(n\right)\\ s_{\mathrm{ij}}\left(n\right)={\mathrm{\&alpha;}}_{\mathrm{ij}}{s}_j(n-{\mathrm{\&tau;}}_{\mathrm{ij}})+v_i\left(n\right)\end{array},$ j=1、2、3

Usually, ground unrest to be average be zero stationary noise, uncorrelated mutually with signal, different microphone places ground unrest is also uncorrelated mutually, then s _rj(n) and s _ijthe cross correlation function R of (n) _rij(τ) be expressed as

j=1、2、3

Distance essence is estimated to adopt the distance-finding method based on time delay, with the time delay of better simply cross-correlation method estimated signal; R is calculated to each possible τ _rij(τ), search maximum value position, obtain signal and arrive the delay time T of i-th microphone to be positioned relative to reference microphone _rij, namely

${\mathrm{\&tau;}}_{\mathrm{rij}}={\mathrm{\&tau;}}_{\mathrm{rj}}-{\mathrm{\&tau;}}_{\mathrm{ij}}=\arg \underset{\mathrm{\&tau;}}{\max }{R}_{\mathrm{rij}}\left(\mathrm{\&tau;}\right),$ j=1、2、3

Because distance rough estimate module has estimated the rough distance d between microphone to be positioned to each sound source _{ij, curr}, now only need thick apart near search for the meticulous distance of microphone in certain limit; The definition velocity of sound is c, rough distance d _{ij, curr}corresponding thick time delay is t _{j, curr}=d _{ij, curr}/ c, at d _{ij, curr}neighbouring Δ d _{ij, curr}in scope, the meticulous distance of search, is converted to corresponding temporal information Δ t by range information _{j, curr}=Δ d _{ij, curr}/ c, then the hunting zone of meticulous time delay is [t _{j, curr}-Δ t _{j, curr}, t _{j, curr}+ Δ t _{j, curr}];

Signal arrival time difference is multiplied by velocity of sound c, obtains the range difference that signal arrives two microphones

d _rij＝(τ _ij-τ _rj)·c＝-τ _rij·c，j＝1、2、3

According to the distance d of reference microphone to a jth sound source _rj, and a jth sound source is to the range difference d of reference microphone and i-th microphone to be positioned _rij, obtain the distance d of i-th microphone to be positioned to a jth sound source _ij

d _ij＝d _rj+d _rij＝d _rj-τ _rij·c(12)

The course of work of described triangle centroid calculation submodule is as follows:

Definition (x _s1, y _s1), (x _s2, y _s2) and (x _s3, y _s3) be respectively three sound source coordinates, d _i1, d _i2, d _i3be respectively the distance of microphone to be positioned to three sound sources.When judging present frame as signal frame, obtaining the meticulous distance d of above-mentioned i-th microphone to be positioned to a jth sound source _ijafterwards, according to geometric relationship, being the center of circle by solving with sound source position, the intersection point of distance three circles that are radius, determining i-th microphone position to be positioned, namely

$\left\{\begin{array}{c}{(x-x_{s1})}^2+{(y-y_{s1})}^2=d_{i1}^2\\ {(x-x_{s2})}^2+{(y-y_{s2})}^2=d_{i2}^2\\ {(x-x_{s3})}^2+{(y-y_{s3})}^2=d_{i3}^2\end{array}\right.---\left(13\right)$

Only have in the ideal case, three circles just can intersect at a point m, and coordinate is (x _m, y _m); And in the ordinary course of things, due to the existence of the error of calculation, this system of equations, without solution, is divided into two kinds of situations without solution: the first is that three circles can not meet at a bit, but surrender a region mutually; The second wherein has at least two circles not have intersection point;

For the first without the situation of solution, select at a distance of three nearest intersection point p ₁(x _p1, y _p1), p ₂(x _p2, y _p2) and p ₃(x _p3, y _p3) composition triangle, ask for this triangle barycenter m, coordinate is (x _m, y _m), as sound source position, namely

$(x_m,y_m)=\frac{1}{3}\underset{i=1}{\overset{3}{\mathrm{\&Sigma;}}}(x_{\mathrm{ni}},y_{\mathrm{ni}})---\left(14\right)$

For the second without solution situation, consider when estimating microphone position, each microphone to be positioned and correction sound source position are all fixing, then these two the round intersection points using former frame to calculate are to serve as this frame intersection point.

The optimum value of a of the present invention is 4; The optimum value of b is 0.05; The optimum value of β is 0.05.

Compared with prior art, the present invention has following beneficial effect:

1, the present invention selects the voice signal of three different frequency bands as the audible signal of three sound sources, can disposable collection isolate three sound sources in microphone position estimation procedure, need not calculated off-line, can realize the On-line Estimation of microphone position.

2, the distance-finding method based on energy and time delay is combined by the present invention, and thick, the essence of successively carrying out distance are estimated, ensure that range finding has less calculated amount and higher precision.

3, the present invention adopts triangle centroid algorithm to obtain the position of each microphone in array, all has corresponding process to various without solution situation, ensures continuation and the stability of positioning result.

Accompanying drawing explanation

The present invention has 14, accompanying drawing, wherein:

Fig. 1 is distributed mike wind array microphone position estimating system functional block diagram.

Fig. 2 is sound-source signal generation module functional block diagram.

Fig. 3 is the functional block diagram of i-th microphone position estimation module.

Fig. 4 is the three round schematic diagram that intersect at a point.

Fig. 5 is that three circles intersect at an area schematic.

Fig. 6 is the non-intersect schematic diagram of three circles.

Distributed microphone array and sound source distribution plan when Fig. 7 is emulation testing.

Fig. 8 is the amplitude-frequency response schematic diagram of three bandpass filter.

The horizontal ordinate estimated result of Fig. 9 to be coordinate be (8,5) m place microphone.

The ordinate estimated result of Figure 10 to be coordinate be (8,5) m place microphone.

The coordinate evaluated error of Figure 11 to be coordinate be (8,5) m place microphone.

The horizontal ordinate estimated result of Figure 12 to be coordinate be (9,2) m place microphone.

The ordinate estimated result of Figure 13 to be coordinate be (9,2) m place microphone.

The coordinate evaluated error of Figure 14 to be coordinate be (9,2) m place microphone.

In figure: 1, sound-source signal generation module, 2, loudspeaker, reference microphone, 3, microphone position estimation module, 4, microphone to be positioned.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described further.

As shown in Figure 1, microphone position estimating system in a kind of distributed mike wind array, comprises sound-source signal generation module 1, loudspeaker, reference microphone 2, multiple microphone 4 to be positioned and multiple microphone position estimation module 3; Described sound-source signal generation module 1 output terminal output signal is converted to sound through loudspeaker and plays in the work-yard of distributed mike wind array; The referenced microphone of this sound 2 and microphone to be positioned 4 received; The signal that reference microphone 2 and microphone to be positioned 4 receive is passed to the microphone position estimation module 3 corresponding with microphone 4 to be positioned simultaneously; The output terminal of described microphone position estimation module 3 exports the coordinate of microphone 4 to be positioned; Described microphone to be positioned 4 and microphone position estimation module 3 one_to_one corresponding;

As shown in Figure 2, described sound-source signal generation module 1 comprises white noise generator and bandpass filter, white noise generator produces white noise signal, described white noise signal passes through the different bandpass filter of three passbands, produce the bandpass signal of three different frequency bands, as the audible signal of three sound sources, input is placed in 3, distributed mike wind array operation place loudspeaker respectively.

As shown in Figure 3, described microphone position estimation module 3 quantity is identical with the quantity of microphone 4 to be positioned, and the working method method of each microphone position estimation module 3 is identical; Described microphone position estimation module 3 comprise signal validation checking submodule, reference microphone 2 sound-source signal segregant module, reference microphone 2 sub-band ground unrest estimator module, microphone to be positioned 4 sound-source signal segregant module, microphone to be positioned 4 sub-band ground unrest estimator module, distance rough estimate submodule, apart from smart estimator module and triangle centroid calculation submodule;

As Figure 4-Figure 6, the course of work of described triangle centroid calculation submodule is as follows:

Definition (x _s1, y _s1), (x _s2, y _s2) and (x _s3, y _s3) be respectively three sound source coordinates, d _i1, d _i2, d _i3be respectively the distance of i-th microphone to be positioned, 4 to three sound sources.When judging present frame as signal frame, obtaining the meticulous distance d of above-mentioned i-th microphone 4 to be positioned to a jth sound source _ijafterwards, the intersection point of three circles that j=1,2,3, according to geometric relationship, is the center of circle by solving with sound source position, distance is radius, determines i-th microphone position to be positioned, namely

$\left\{\begin{array}{c}{(x-x_{s1})}^2+{(y-y_{s1})}^2=d_{i1}^2\\ {(x-x_{s2})}^2{+(y-y_{s2})}^2=d_{i2}^2\\ {(x-x_{s3})}^2+{(y-y_{s3})}^2=d_{i3}^2\end{array}\right.$

Only have in the ideal case, three circles just can intersect at a point m, and coordinate is (x _m, y _m) (as shown in Figure 4); And in the ordinary course of things, due to the existence of the error of calculation, this system of equations, without solution, is divided into two kinds of situations without solution: the first is that three circles can not meet at a bit, but surrender a region (as shown in Figure 5) mutually; The second wherein has at least two circles not have intersection point (as shown in Figure 6);

For the first without the situation of solution, select at a distance of three nearest intersection point p ₁(x _p1, y _p1), p ₂(x _p2, y _p2) and p ₃(x _p3, y _p3) composition triangle, ask for this triangle barycenter m, coordinate is (x _m, y _m), as sound source position, namely

$(x_m,y_m)=\frac{1}{3}\underset{i=1}{\overset{3}{\mathrm{\&Sigma;}}}(x_{\mathrm{ni}},y_{\mathrm{ni}})---\left(14\right)$

For the second without solution situation, consider when estimating microphone position, each microphone 4 to be positioned and correction sound source position are all fixing, then these two the round intersection points using former frame to calculate are to serve as this frame intersection point.

The optimum value of a of the present invention is 4; The optimum value of b is 0.05; The optimum value of β is 0.05.

For verifying advantage of the present invention, carry out following emulation testing.Assuming that the region of a 10m × 10m, the coordinate on four summits is respectively (0,0) m, (0,10) m, (10,0) m and (10,10) m.The coordinate of three calibration sound sources is respectively (0,0) m, (0,1) m and (1,0) m, and reference microphone coordinate is (1,1) m.Have the microphone of 8 positions to be determined in region, and the gain of each microphone is calibrated.Calibration sound source, reference microphone, microphone position to be positioned distribution are as shown in Figure 7.

If three bandpass filter are 8 rank Butterworth wave filters, cut-off frequecy of passband is respectively [450Hz, 650Hz], [950Hz, 1150Hz] and [1450Hz, 1650Hz], and coefficient is respectively:

(1) [450Hz, 650Hz] bandpass filter:

B1=1.0×10 ^-4×[0.021505689961486,0,-0.086022759845944,0,0.129034139768916,0,-0.086022759845944,0,0.021505689961486];

A1=[1.0,-7.619560406446450,25.571208572772093,-49.362204407327965,59.944291732842998,-46.892314668407494,23.076325245729549,-6.532148379124553,0.814405997727282];

(2) [950Hz, 1150Hz] bandpass filter:

B2=1.0×10 ^-4×[0.021505687637543,0,-0.086022750550173,0,0.129034125825259,0,-0.08602275055017,0,0.021505687637543];

A2=[1.0,-7.147003817816104,22.953870141090817,-43.181776132672987,51.995025280573671,-41.021175158245249,20.714374288994392,-6.127031864547846,0.814405997727283];

(3) [1450Hz, 1650Hz] bandpass filter:

B3=1.0×10 ^-4×[0.021505687407555,0,-0.086022749630222,0,0.129034124445332,0,-0.08602274963022,0,0.021505687407555];

A3=[1.0,-6.399791880553000,19.157164010994535,-34.615721568256149,41.140865143886366,-32.883785334287396,17.288132742285850,-5.486456951495592,0.814405997727280].

The frequency response curve of three wave filters as shown in Figure 8.

Near distance rough estimate, search for meticulous distance within the scope of 0.1m, velocity of sound c is approximate is taken as 340 meter per seconds.Sample frequency is 16KHz, and data processing frame length is 0.2 second (namely frame length M is 3200 points).

Table 1 provides each microphone position estimated result, from table 1, when, snr of received signal comparatively near in microphone distance sound source is larger, only less based on energy ranging localization error, but signal to noise ratio (S/N ratio) reduces, and positioning error increases.And two kinds of distance-finding methods are combined, revised energy range measurement by time delay distance-finding method, no matter signal to noise ratio (S/N ratio) size, positioning error is all smaller.

Table 1 microphone position estimated result

The microphone that Fig. 9-Figure 14 is (8,5) m and (9,2) m with coordinate is that example provides each frame estimated result in position fixing process.From Fig. 9-Figure 14, what dotted line represented only has fluctuation all the time based on energy positioning result, and solid line represents is convergent tendency based on energy and the every frame alignment result of time delay associated methods, and speed of convergence is very fast, therefore adopts associated methods can realize rapid, stable microphone position to estimate.

In calculated amount, if only adopt the distance-finding method based on time delay, directly carry out cross-correlation calculation, then, under 16KHz sampling rate condition, when calculating 0.2 second, the cross correlation function of long data needs to carry out about 1.024 × 10 ⁷secondary multiplying and 1.023 × 10 ⁷sub-addition computing; And the energy first calculating two paths of signals carries out distance rough estimate, then carry out cross-correlation calculation a small amount of some place (under this simulated conditions, being equivalent to 11 sampled points within the scope of 0.1m), only need carry out about 4.16 × 10 ⁴secondary multiplying and 4.159 × 10 ⁴sub-addition computing.Calculated amount is down to only based on about 1/240 of time delay distance-finding method.

Claims (2)

1. a microphone position estimating system in distributed mike wind array, is characterized in that: comprise sound-source signal generation module (1), loudspeaker, reference microphone (2), multiple microphone to be positioned (4) and multiple microphone position estimation module (3); Described sound-source signal generation module (1) output terminal output signal is converted to sound through loudspeaker and plays in the work-yard of distributed mike wind array; The referenced microphone of this sound (2) and microphone to be positioned (4) received; The signal that reference microphone (2) and microphone to be positioned (4) receive is passed to the microphone position estimation module (3) corresponding with microphone to be positioned (4) simultaneously; The output terminal of described microphone position estimation module (3) exports the coordinate of microphone to be positioned (4); Described microphone to be positioned (4) and microphone position estimation module (3) one_to_one corresponding;

The method of work of described sound-source signal generation module (1) comprises the following steps:

Described sound-source signal generation module (1) comprises white noise generator and bandpass filter, white noise generator produces white noise signal, described white noise signal passes through the different bandpass filter of three passbands, produce the bandpass signal of three different frequency bands, as the audible signal of three sound sources, input is placed in 3, distributed mike wind array operation place loudspeaker respectively; If the unit impulse response of three bandpass filter is respectively h _jn (), j=1,2,3, carries out filtering to white noise signal x (n) that white noise generator produces respectively, obtains the bandpass signal s of three different frequency bands _j(n), j=1,2,3,

s _j(n)＝x(n)*h _j(n)，j＝1、2、3

Wherein, the convolution algorithm in symbol " * " representative digit signal transacting field; N represents white noise signal x, unit impulse response h ₁, h ₂, h ₃the sequence number of each sampled value;

Described microphone position estimation module (3) quantity is identical with the quantity of microphone to be positioned (4), and the working method method of each microphone position estimation module (3) is identical; I-th microphone position estimation module (3) corresponding to i-th microphone to be positioned (4), microphone position estimation module comprise signal validation checking submodule, reference microphone (2) sound-source signal segregant module, reference microphone (2) sub-band ground unrest estimator module, microphone to be positioned (4) sound-source signal segregant module, microphone to be positioned (4) sub-band ground unrest estimator module, distance rough estimate submodule, apart from smart estimator module and triangle centroid calculation submodule;

Whether described signal validation checking submodule detects input signal effective, and the signal s that computing reference microphone (2) receives _rthe short-time energy E of (n) every frame _r

Wherein, M represents frame length, and start represents that present frame is at original received signal sequence s _rreference position in (n); Relatively E _rwith signal/noise decision threshold E _thrif, E _r<E _thr, judge that present frame is as noise frame, otherwise, judge that present frame is as signal frame;

When judging present frame as noise frame, estimating background noise comprising ENERGY E _min, upgrade availability deciding threshold value E _thr; This threshold value update method is

ifE _min＜E _r

E _min＝E _r

E _thr＝aE _min

endif

Wherein, a is a constant, and the span of a is 1<a<100;

Described reference microphone (2) sound-source signal segregant module utilizes three bandpass filter identical with coefficient in sound-source signal generation module (1) to be separated by three sound-source signals; The unit impulse response of these three bandpass filter is also h _jn (), j=1,2,3, to reference microphone (2) Received signal strength s _rn () carries out filtering respectively, obtain the signal s of three different frequency bands _rj(n), j=1,2,3, namely

s _rj(n)＝s _r(n)*h _j(n)，j＝1、2、3

When judging present frame as noise frame, described reference microphone (2) sub-band ground unrest estimator module estimates the ENERGY E of three sub-bands respectively _rj, j=1,2,3,

By E _rj, j=1,2,3, with front reference microphone (2) sub-band background noise energy estimated result ε _{rj, old}smoothing, sharpening result is as current background noise energy estimated value ε _{rj, curr},

ε _rj,curr＝(1-b)·ε _rj,old+b·E _rj，j＝1、2、3

Wherein, b is smoothing factor, represents present energy E _rj, j=1,2,3, proportion when level and smooth, the span of b is 0<b<1;

Described microphone to be positioned (4) sound-source signal segregant module utilizes three bandpass filter identical with coefficient in sound-source signal generation module (1) to be separated by three sound-source signals; The unit impulse response of these three bandpass filter is also h _jn (), j=1,2,3, to microphone to be positioned (4) Received signal strength s _in () carries out filtering respectively, obtain the signal of three different frequency bands, namely

s _ij(n)＝s _i(n)*h _j(n)，j＝1、2、3

When judging present frame as noise frame, described microphone to be positioned (4) sub-band ground unrest estimator module estimates the ENERGY E of three sub-bands respectively _ij, j=1,2,3,

Again by E _ij, j=1,2,3, with front once microphone to be positioned (4) sub-band background noise energy estimated result ε _{ij, old}smoothing, sharpening result is as current background noise energy estimated value ε _{ij, curr},

ε _ij,curr＝(1-b)·ε _ij,old+b·E _ij，j＝1、2、3

Wherein, b is smoothing factor, represents present energy E _ij, j=1,2,3, proportion when level and smooth, the span of b is 0<b<1;

The described distance rough estimate submodule course of work is as follows:

Definition footmark r represents reference microphone (2), and footmark i represents i-th microphone to be positioned (4), and footmark j represents a jth sound source, i.e. a jth loudspeaker, j=1,2,3, d _ijrepresent the Euclidean distance between a jth sound source and i-th microphone to be positioned (4), (x _r, y _r) and (x _j, y _j) represent the coordinate of reference microphone (2) and a jth sound source, d respectively _rjrepresent the Euclidean distance between a jth sound source and reference microphone (2) ε _rjt () is the estimation of t reference microphone (2) sub-band background noise energy, ε _ijt sub-band background noise energy that () is t i-th microphone to be positioned (4) place is estimated; Calibrate in microphone gain, when the microphone output signal energy namely under the identical sound intensity is identical, when judging present frame as signal frame, then i-th current microphone to be positioned (4) is to the distance rough estimate of a jth sound source for

For improving the accuracy that follow-up distance essence is estimated, by current distance rough estimate result j=1,2,3, with previous sharpening result d _{ij, old}smoothing, obtain current distance rough estimate sharpening result d _{ij, curr}

Wherein, β is smoothing factor, represents current distance rough estimate result proportion in smoothing process, the span of β is 0< β <1;

Described distance essence estimator module routine is as follows:

Definition α _rjand α _ijbe respectively sound propagates into reference microphone (2) and i-th microphone to be positioned (4) decay factor from a jth sound source, τ _rjand τ _ijbe respectively sound propagates into reference microphone (2) and i-th microphone to be positioned (4) time delay from sound source j, v _r(n) and v _in () is respectively the ground unrest at reference microphone (2) and i-th microphone to be positioned (4) place, when judging present frame as signal frame, what reference microphone (2) received with i-th microphone to be positioned (4) comes from same sound source s _jsignal be respectively

s _rj(n)＝α _rjs _j(n-τ _rj)+v _r(n)

，j＝1、2、3

s _ij(n)＝α _ijs _j(n-τ _ij)+v _i(n)

Usually, ground unrest to be average be zero stationary noise, uncorrelated mutually with signal, different microphone places ground unrest is also uncorrelated mutually, then s _rj(n) and s _ijthe cross correlation function R of (n) _rij(τ) be expressed as

R _rij(τ)＝E[s _rj(n)s _ij(n-τ)]＝α _rjα _ijE[s _rj(n-τ _rj)s _ij(n-τ _ij-τ)],j＝1、2、3

Wherein, τ is the variable representing time delay, and E [.] represents the computing asking expectation;

Distance essence is estimated to adopt the distance-finding method based on time delay, with the time delay of better simply cross-correlation method estimated signal; R is calculated to each possible τ _rij(τ), search maximum value position, obtain signal and arrive the delay time T of i-th microphone to be positioned (4) relative to reference microphone (2) _rij, namely

Because distance rough estimate module has estimated the rough distance d between microphone to be positioned (4) to each sound source _{ij, curr}, now only need thick apart near search for the meticulous distance of microphone in certain limit; The definition velocity of sound is c, rough distance d _{ij, curr}corresponding thick time delay is t _{j, curr}=d _{ij, curr}/ c, at d _{ij, curr}neighbouring Δ d _{ij, curr}in scope, the meticulous distance of search, is converted to corresponding temporal information Δ t by range information _{j, curr}=Δ d _{ij, curr}/ c, then the hunting zone of meticulous time delay is [t _{j, curr}-Δ t _{j, curr}, t _{j, curr}+ Δ t _{j, curr}];

Signal arrival time difference is multiplied by velocity of sound c, obtains the range difference that signal arrives two microphones

d _rij＝(τ _ij-τ _rj)·c＝-τ _rij·c，j＝1、2、3

According to the distance d of reference microphone (2) to a jth sound source _rj, and a jth sound source is to the range difference d of reference microphone (2) and i-th microphone to be positioned (4) _rij, obtain the meticulous distance d of microphone to be positioned (4) to a jth sound source _ij

d _ij＝d _rj+d _rij＝d _rj-τ _rij·c

The course of work of described triangle centroid calculation submodule is as follows:

Definition (x _s1, y _s1), (x _s2, y _s2) and (x _s3, y _s3) be respectively three sound source coordinates, d _i1, d _i2, d _i3be respectively the meticulous distance of i-th microphone to be positioned (4) to three sound sources; When judging present frame as signal frame, obtaining the meticulous distance d of above-mentioned i-th microphone to be positioned (4) to a jth sound source _ijafterwards, the intersection point of three circles that j=1,2,3, according to geometric relationship, is the center of circle by solving with sound source position, distance is radius, determines i-th microphone position to be positioned, namely

Only have in the ideal case, three circles just can intersect at a point m, and coordinate is (x _m, y _m); And in the ordinary course of things, due to the existence of the error of calculation, this system of equations, without solution, is divided into two kinds of situations without solution: the first is that three circles can not meet at a bit, but surrender a region mutually; The second wherein has at least two circles not have intersection point;

For the first without the situation of solution, select at a distance of three nearest intersection point p ₁(x _p1, y _p1), p ₂(x _p2, y _p2) and p ₃(x _p3, y _p3) composition triangle, ask for this triangle barycenter m, coordinate is (x _m, y _m), as i-th microphone position to be positioned, namely

For the second without solution situation, consider when estimating microphone position, each microphone to be positioned (4) and correction sound source position are all fixing, then these two the round intersection points using former frame to calculate are to serve as this frame intersection point.

2. microphone position estimating system in a kind of distributed mike wind array according to claim 1, is characterized in that: the optimum value of described a is 4; The optimum value of b is 0.05; The optimum value of β is 0.05.