CN101902680B - Design method of virtual coupled space based on active control - Google Patents

Abstract

The invention discloses a design method for realizing a virtual coupled space based on active control. The virtual coupled space system designed by using the method can, in a common rectangular space, realize sound field distribution in a certain target coupled space. The method can realize sound field in the coupled space at small cost, and achieves good effect.

Description

Method for designing based on the virtual coupled space of active control

One. technical field

The present invention relates to a kind of method for designing of the virtual coupled space based on active control.

Two. background technology

Sound system has had the history above 50 years in the variable cells from coming out.More representational resonance (AR) system of receiving aid (Parkin P H and Morgan K. " Assisted resonance " in the royal festival hall, london.J.Sound Vib., 1965; 2 (1): 74-85.), reverberation room ambiophonic system (Harold B-M and Vincent M.Sound control techniquesfor the legitimate theatre and opera.Journal of the Audio Engineering Society, 1961; 9 (3): 184-186.), multichannel reverberation (MCR) system (Franssen N V.Sur i ' amplification des champs acoustiques.Acustica, 1968; 20:315-323.), sound system (VRAS in the acoustics control system (ACS), variable cells; Poletti, M., andEllison, S.Control of early and late energy in rooms with the variable room acoustics system.J.Acoust.Soc.Am.114, (2003) expansion multichannel (EMCR) system .2341.).And the domestic and international up to now patent of invention of not finding correlation technique as yet.

More than these systems all only can change reverberation time in the space, can not simulate peculiar sound field in the acoustic space of a labyrinth exactly, such as coupled room.Because coupled room can provide a kind of sound field of taking into account definition and reverberation sense, so introduced the element of coupled room in the design of the modern hall more and more.But the coupled room utilance of introducing is very low even can not utilize fully, has brought more serious space resources waste problem.

Sound system in the variable cells that the present invention proposes, can be more exactly in a common space the approximate sound field that realizes out in the coupled room being had distribute, can either can obtain the sound field of better quality again at design time save space.

Three. summary of the invention

The purpose of this invention is to provide a kind of can be in common coffin, produce the system that approaches the sound field in the coupled room.This method obtains the aim parameter p of active control by measuring or find the solution sound field in the target coupled room earlier _c, subscript c means coupling (coupled).Utilize active control strategy then, in common coffin, lay control sound source and error microphone, by the intensity of optimal control sound source, the total acoustic pressure that makes acoustic source in the coffin, the control sound source that the present invention introduced produce approaches the acoustic pressure p that acoustic source produces in the target coupled room _c

The present invention is achieved through the following technical solutions:

A) model of establishing target coupled room, the structure of subspace that wherein comprises sound source is identical with the object space of control, the method of utilizing mode to launch is united the two sub spaces condition that acoustic pressure equates on coupling opening, utilizes the Variational Calculation method, and finding the solution the acoustic pressure expression that obtains in the principal subspace (is p _c),

$p_c\left(t\right)=-\mathrm{jk\ρc}{\∫\∫\∫}_{S_{\mathrm{\ω}}}{/G}_a\left(r\right|r_0)S_{\mathrm{\ω}}\left(r_0\right){\mathrm{dr}}_0+\mathrm{jk\ρc}{\∫\∫}_{S_0}{G}_a\left(r\right|r_0)u_0\left(r_0\right){\mathrm{dr}}_0---\left(1\right)$

Wherein

For the particle velocity on the coupling opening distributes, by changing G wherein _b(with space V among Fig. 1 _bStructure directly related) can reach the purpose that changes coupling subspace structure, to produce the effect of different coupling sound fields; ρ is an atmospheric density, and c is airborne acoustic velocity, and k is a wave number, S _ω(r) be the intensity of distributed sound source, S _aAnd S _bBe respectively the internal surface area in two sub spaces.

For containing subspace, the source (V among Fig. 1 _aThe space) not with the passive subspace (V among Fig. 1 _bThe space) when coupling acoustic pressure wherein.

G _aAnd G _bBe respectively the Green's function in two sub spaces, have expression formula respectively

Eigenfunction φ _n, eigenvalue η _nAverage Λ with eigenfunction _nBe respectively,

$\×\cos (q_{{\mathrm{zn}}_z}\frac{\mathrm{\πz}}{l_z}+j{\mathrm{\β}}_{z0}\frac{{\mathrm{kl}}_z}{{\mathrm{\πq}}_{{\mathrm{zn}}_z}})$

${\mathrm{\&eta;}}_{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000167955500013.png"\; state="\{\{state\}\}">n</figure-callout>}}^2={\left(\frac{{\mathrm{\&pi;q}}_{{\mathrm{xn}}_x}}{l_x}\right)}^2+{\left(\frac{{\mathrm{\&pi;q}}_{{\mathrm{yn}}_y}}{l_y}\right)}^2+{\left(\frac{{\mathrm{\&pi;q}}_{{\mathrm{zn}}_z}}{l_z}\right)}^2---\left(3\right)$

Λ _n＝L _xL _yL _z (4)

Wherein,

$L_x=\frac{1}{2}\&PlusMinus;\frac{1}{{2\mathrm{\&pi;q}}_{{\mathrm{xn}}_x}}\sin \left({\mathrm{\&pi;q}}_{{\mathrm{xn}}_x}\right),$ $L_y=\frac{1}{2}\&PlusMinus;\frac{1}{{2\mathrm{\&pi;q}}_{{\mathrm{yn}}_y}}\sin \left({\mathrm{\&pi;q}}_{{\mathrm{yn}}_y}\right),$ $L_z=\frac{1}{2}\&PlusMinus;\frac{1}{2\mathrm{\&pi;}{q}_{{\mathrm{zn}}_z}}\sin \left({\mathrm{\&pi;q}}_{{\mathrm{zn}}_z}\right)---\left(8\right)$

n _x, n _y, n _zDuring for even number, L in the formula (8) _x, L _yAnd L _zExpression in get plus sige respectively; n _x, n _y, n _zDuring for odd number, get negative sign respectively.β _X0And β _XlBe the ratio acoustic admittance on x direction two parallel planes (corresponding x=0 plane and x=l plane respectively), β _Y0And β _YlBe the ratio acoustic admittance on y direction two parallel planes, β _Z0And β _ZlBe the ratio acoustic admittance on z direction two parallel planes.

B) one with the target coupled room in the ordinary rectangular space of principal subspace same structure in, lay control sound source and error microphone.M * N control sound source is parallel and big or small identical in the coupling opening with the target coupled room with the arranged in form of the capable N row of M, in the plane of distance lambda/4; M * N microphone is parallel and big or small identical in the coupling opening with the target coupled room with the arranged in form of the capable N row of M, and in the plane of distance lambda/8, λ wherein is the acoustic pressure the controlled wavelength at highest frequency.

The target of control is approached the acoustic pressure p of same position in the target coupled room for this total acoustic pressure _c, cost function is,

$J={|p_p+p_s-p_c|}^2$

$=q_s^{*}{\mathrm{aq}}_s+q_s^{*}b+q_s{b}^{*}+c---\left(9\right)$

Wherein,

C=(Z _pq _p-p _c) ^*(Z _pq _p-p _c); p _pBe the expression matrix of elementary sound source generation acoustic pressure, p _sBe the expression matrix of control sound source generation acoustic pressure, p _cFor when elementary sound source as for virtual coupled space in the time produce the expression matrix of acoustic pressure.q _pBe the intensity matrix of elementary sound source, q _sIntensity matrix for the control sound source.Z _pBe the transfer function of elementary sound source to error microphone, Z _sBe the transfer function of control sound source to error microphone, they have following expression,

Wherein

Through optimizing, obtaining the optimal control strength of sound source be

q _s＝-b/a (12)

Characteristics of the present invention are: by the acoustic pressure of theoretical and numerical solution target coupled room sound field, perhaps obtain to lay the acoustic pressure at error microphone place by the method for in existing coupled room, directly measuring, utilize the method for active control again, can realize in general spatial more exactly that the sound field in the coupled room distributes.The present invention than before the reverberation control system, target is clearer and more definite, realizes accurately, and can be by changing the sound field that Control Parameter easily realize different structure target coupled room.

Four. description of drawings

The schematic diagram of Fig. 1 target coupled room, V _aBe active subspace, V _bBe passive subspace, S ₀Be coupling opening

Active guidance system lays figure, the V among this space and Fig. 1 in Fig. 2 ordinary rectangular space _aYardstick is identical, gets the xy section of height z=1.5m, r _eFor error microphone lays face, r _sFor the control sound source lays face, C1 is y=2, and the observation line of z=1.5, C2 are x=4, the observation line of z=1.5.

Fig. 3 is along the control effect prediction figure as the observation line C1 direction among Fig. 2, and transverse axis is x ∈ [0,5] m, and the longitudinal axis is that the relative sound pressure level (SPL) on the C1 line is poor.

Five. embodiment

The present invention is described in detail with reference to accompanying drawing below in conjunction with embodiment:

The target that the present invention realizes is to be produced as shown in Figure 1 V in the coupled room in the ordinary rectangular space _aIn sound field.

At first, try to achieve target acoustic pressure p according to formula (1-8) _cIn this example, V _aBe the principal space, sound source is positioned at wherein, and its 3 dimension is of a size of 5 * 4 * 3m ³, its inwall is set at β than acoustic admittance _a=0.07663+0.06425i is converted into acoustic absorptivity and is about 0.4.V _bBe inferior space, no sound source in it generally is used to regulate V _aIn acoustic characteristic, distribute reverberation time length etc. such as sound field.V _b3 dimensions be of a size of 7 * 4 * 3m ³, its inwall is set at β than acoustic admittance _b=0.0322-0.0383i is converted into acoustic absorptivity and is about 0.2.In the separation in the middle of two sub spaces, having area in centre is 1 * 1m ²Coupling opening S ₀, elementary sound source position is fixed on (1.0,1.0,1.0) m place.

After trying to achieve the acoustic pressure distribution in the target coupled room, get some somes placement error microphones, select as r among Fig. 2 in this example _eOn the plane 9 point, r _eThe plane is identical, parallel with coupling opening size in the target coupled room, and distance lambda/8.Guide sound source distribution is in r _sThe plane is apart from coupling opening λ/4.λ wherein is the acoustic pressure the controlled wavelength at highest frequency.Fig. 2 is shown as the xy plane of height z=1.5m, S ₀Be the position at coupling opening place in the virtual target coupled room, C1 is for passing through the observation line of center, space along the x direction.Utilize formula (12), try to achieve the intensity matrix of control sound source.

According to as above condition, the control effect prediction figure that numerical simulation obtains as shown in Figure 3.Curve is under the 250Hz frequency, the distribution map of sound pressure level C1 curve in Fig. 2, transverse axis is the C1 line along the x direction, the longitudinal axis is that standard sound pressure is differential, the square line is that the relative acoustic pressure on the C1 line distributes in the ordinary rectangular space, triangle line is that the relative acoustic pressure on the C1 line distributes in the target coupled room, and the open circles line is that the relative acoustic pressure after the active control of use distributes in the ordinary rectangular space.The existence that can see coupled room has suppressed the acoustic pressure distribution periodic undulations that some mode (perhaps being the vibration shape) causes too strongly in the space significantly, and is helpful to homogenizing acoustic pressure spatial distribution.So introduce active guidance system in general spatial, the constructing virtual coupled room can be controlled the sound field in the coffin effectively, and the acoustic pressure of approaching when having coupled room distributes.

Claims (2)

1. the method for designing of a virtual coupled space system, it is characterized in that realizing sound system in a kind of new variable cells by in common coffin, introducing active guidance system, make in the common coffin and to produce the sound field that is similar in the coupled room to be had, and can may further comprise the steps by changing the coupled room of Control Parameter simulation different structure:

(1) Green's function in the use coffin and the coupling condition in two spaces are found the solution the acoustic pressure that obtains the sound field in the target coupled room, perhaps obtain the acoustic pressure of the sound field in the existing coupled room by measurement, and with the target of this acoustic pressure as active control;

(2) use the active control strategy close in the space, arrange control sound source and error microphone, the optimal control strength of sound source, concrete active control strategy is as follows:

1) in coupling opening with the target coupled room in the parallel and big or small identical plane, both are at a distance of λ/4 with the arranged in form of the capable N of M row for M * N control sound source, and λ is the wave length of sound of the highest frequency correspondence of the acoustic pressure that will control;

2) in coupling opening with the target coupled room in the parallel and big or small identical plane, both are λ/8 apart with the arranged in form of the capable N row of M for M * N microphone;

3) with the acoustic pressure of former coffin sound field and the total acoustic pressure and the p as claimed in claim 2 of control sound source generation _cThe square value of difference as cost function secondary source intensity is optimized, even J=|p _p+ p _s-p _c| ², p wherein _pBe the acoustic pressure that the original sound source in the former coffin produces, p _sAcoustic pressure for control sound source generation in this coffin.

2. the method for designing of virtual coupled space system as claimed in claim 1, it is characterized in that, determine the target that system's control will reach, it is the acoustic pressure of the sound field in the target coupled room, can obtain by the theoretical model prediction, also can obtain, be made as p by in the coupled room of a reality, measuring _c, subscript c means coupling (coupled).

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