CN101290347A - Method for obtaining still acoustic source acoustic field image by regular sound array and single video camera - Google Patents

Abstract

The invention relates to a method for using a regular acoustic array and a single camera to obtain images of a static sound source sound field, which belongs to the noise analysis and control technical field. At first, a microphone array and a camera are arranged; the microphone array obtains a sound pressure signal of a measured sound source, and the camera obtains an image of the measured sound source; the sound pressure signal is subject to the beam forming treatment to obtain a sound field feature function distribution map of the measured sound source, and the sound field feature function distribution map and the image of the measured sound source are superimposed in a space coordinate. The method makes the position analysis of the static sound source simpler and more intuitive, and provides a more accurate evidence for further noise-reducing work.

Description

Obtain the method for static sound source sound field image with regular acoustic array and single camera

Technical field

The present invention relates to the method that regular acoustic array of a kind of usefulness and single camera obtain static sound source sound field image, belong to noise analysis and control technology field.

Background technology

Modern society's noise has become one of environmental pollution and has originated greatly.To handle noise targetedly, at first need to obtain the sound field of noise source more accurately, each sound source is distinguished.And the visual positioning analysis of noise source that can make of sound field is more directly perceived, thereby for further noise abatement work provides foundation, all significant to noise measurement and improvement work.

At present, in the world at the motion sound source of vehicles class, mainly contain acoustical holography method and array approach to what its sound field was carried out study of measurement analysis.It is very big that holography method measurement motion acoustic field is influenced by Doppler effect, and its engineering practical application has been subjected to limitation.Compare with holographic technique, the application of array technique in identification of sound source research is more extensive.But, use array technique can only obtain the sound field characteristics function distribution plan of tested sound source, the position of tested sound source can not show intuitively.

Summary of the invention

The objective of the invention is to propose the method that regular acoustic array of a kind of usefulness and single camera obtain static sound source sound field image, make the positioning analysis simple, intuitive more of static sound source.

The method that regular acoustic array of usefulness that the present invention proposes and single camera obtain static sound source sound field image may further comprise the steps:

(1) with tested sound source at a distance of D place layout rules microphone array, a video camera is set at the center of regular microphone array;

(2) start above-mentioned video camera and microphone array, video camera obtains a two field picture of tested sound source, stops microphone array after setting the period, and microphone array obtains the sound pressure signal of tested sound source in this period;

(3) sound pressure signal that above-mentioned microphone array is obtained carries out beam forming and handles, obtain plane M tested sound source place and parallel with microphone array go up any 1 s (ε, η) in the above-mentioned period from t ₁To t ₂Sound field characteristics function in time:

$W_p(\mathrm{\ϵ},\mathrm{\η})={\∫}_{t_1}^{t_2}{P}^2(t,\mathrm{\ϵ},\mathrm{\η})\mathrm{dt},$ Wherein, $P(t,\mathrm{\ϵ},\mathrm{\η})=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{p}_i(t+\frac{r_i(t,\mathrm{\ϵ},\mathrm{\η})}{c}),$

p _i(t) be t moment i sound pressure signal that microphone receives, t ₁＜t＜t ₂, r _i(t, ε, η) be t constantly any 1 s on the M face (ε, η) with i microphone between physical distance, c is the velocity of sound, N is the microphone number, as if the time interval between the every two field picture of video camera be Δ T, establish and obtained t ₀The image of tested sound source is constantly got $t_1=t_0-\frac{1}{2}\mathrm{\ΔT},$ $t_2=t_0+\frac{1}{2}\mathrm{\ΔT},$ Travel through the plane M at tested sound source place, obtain the sound field characteristics function distribution plan of plane M;

(4) video image that the sound field characteristics function distribution plan and the above-mentioned video camera of above-mentioned tested sound source obtained carries out the volume coordinate stack.

In the said method, the arrangement form of described microphone array is any in a word, cross, X-shaped or the circular regular microphone array.

The method that regular acoustic array of usefulness that the present invention proposes and single camera obtain static sound source sound field image, utilize regular microphone array to obtain the sound field data of tested sound source, utilize video camera to obtain the image of tested sound source, with the fusion that superposes of the picture of the sound field characteristics functional arrangement of tested sound source and tested sound source, realize the fusion of sound field and image, the positioning analysis that makes static sound source is simple, intuitive more, for further noise reduction work provides foundation more accurately.

Description of drawings

Fig. 1 is to use the place of the inventive method to arrange synoptic diagram.

Among Fig. 1, the 1st, static sound source, the 2nd, video camera, the 3rd, microphone array, the 4th, preposition amplification interface box, the 5th, signal sampler, the 6th, computer.

Embodiment

Introduce the rule-based acoustic array of the present invention's proposition and the method for obtaining static sound source sound field image of single camera in detail below in conjunction with accompanying drawing:

(1) as shown in Figure 1, with tested static sound source 1 at a distance of D place layout rules microphone array 3, what adopt among the figure is circular array, at video camera 2 of center arrangement of regular microphone array, the span of D is 2～6 meters.

(2) start above-mentioned video camera and microphone array, video camera obtains a two field picture of tested sound source, stops the work of microphone array after setting the period, the sound pressure signal of tested sound source in microphone array obtains during this period of time.As shown in Figure 1, the sound pressure signal of 4 pairs of tested sound sources of signal front interface case amplifies, and improves signal to noise ratio (S/N ratio).Signal sampler 5 will carry out filtering through the sound pressure signal behind the front interface case 4 and amplify, and be converted into digital signal.6 pairs of sound pressure signals of computer and vision signal are gathered and are handled.

(3) sound pressure signal that above-mentioned microphone array is obtained carries out beam forming and handles, obtain plane M tested sound source place and parallel with microphone array go up any 1 s (ε, η) in the above-mentioned period from t ₁To t ₂Sound field characteristics function in time:

$W_p(\mathrm{\ϵ},\mathrm{\η})={\∫}_{t_1}^{t_2}{P}^2(t,\mathrm{\ϵ},\mathrm{\η})\mathrm{dt},$ Wherein, $P(t,\mathrm{\ϵ},\mathrm{\η})=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{p}_i(t+\frac{r_i(t,\mathrm{\ϵ},\mathrm{\η})}{c}),$

p _i(t) be t moment i sound pressure signal that microphone receives, t ₁＜t＜t ₂, r _i(t, ε, η) be t constantly any 1 s on the M face (ε, η) with i microphone between physical distance, c is the velocity of sound, N is the microphone number, as if the time interval between the every two field picture of video camera be Δ T, establish and obtained t ₀The image of tested sound source is constantly got $t_1=t_0-\frac{1}{2}\mathrm{\ΔT},$ $t_2=t_0+\frac{1}{2}\mathrm{\ΔT},$ Travel through the plane M at tested sound source place, obtain the sound field characteristics function distribution plan of plane M.

(4) the sound field characteristics function distribution plan of above-mentioned tested sound source and the video image of above-mentioned video camera are carried out the volume coordinate stack.

Claims (2)

1, regular acoustic array of a kind of usefulness and single camera obtain the method for static sound source sound field image, it is characterized in that this method may further comprise the steps:

(1) with tested sound source at a distance of D place layout rules microphone array, a video camera is set at the center of regular microphone array;

(2) start above-mentioned video camera and microphone array, video camera obtains a two field picture of tested sound source, stops microphone array after setting the period, and microphone array obtains the sound pressure signal of tested sound source in this period;

(3) sound pressure signal that above-mentioned microphone array is obtained carries out beam forming and handles, obtain plane M tested sound source place and parallel with microphone array go up any 1 s (ε, η) in the above-mentioned period from t ₁To t ₂Sound field characteristics function in time:

$W_p(\mathrm{\ϵ},\mathrm{\η})={\∫}_{t_1}^{t_2}{P}^2(t,\mathrm{\ϵ},\mathrm{\η})\mathrm{dt},$ Wherein, $P(t,\mathrm{\ϵ},\mathrm{\η})=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{p}_i(t+\frac{r_i(t,\mathrm{\ϵ},\mathrm{\η})}{c}),$

p _i(t) be t moment i sound pressure signal that microphone receives, t ₁＜t＜t ₂, r _i(t, ε, η) be t constantly any 1 s on the M face (ε, η) with i microphone between physical distance, c is the velocity of sound, N is the microphone number, as if the time interval between the every two field picture of video camera be Δ T, establish and obtained t ₀The image of tested sound source is constantly got $t_1=t_0-\frac{1}{2}\mathrm{\ΔT},$ $t_2=t_0+\frac{1}{2}\mathrm{\ΔT},$ Travel through the plane M at tested sound source place, obtain the sound field characteristics function distribution plan of plane M;

(4) video image that the sound field characteristics function distribution plan and the above-mentioned video camera of above-mentioned tested sound source obtained carries out the volume coordinate stack.

2, the method for claim 1, the arrangement form that it is characterized in that described microphone array are any in a word, cross, X-shaped or the circular regular microphone array.