CN201707126U - Environmental noise monitoring device capable of distinguishing direction of noise source - Google Patents

Abstract

The utility model discloses an environmental noise monitoring device capable of distinguishing the direction of a noise source, which is characterized in that a noise measuring front end of an environmental noise monitoring system is formed by a microphone A, a microphone B, a microphone C and a microphone D which have consistent performance parameters, and the four microphones are distributed on the adjacent four vertices of a regular hexahedron in a regular hexahedral shape; the microphone A is taken as an origin, and the distance between the microphone A as well as the microphone B, the microphone C and the microphone D is of a side length d of the regular hexahedron; and a connecting line of the microphone A and the microphone B is taken as an X-axis, a connecting line of the microphone A and the microphone C is taken as a Y-axis, and a connecting line of the microphone A and the microphone D is taken as a Z-axis so as to form a rectangular coordinate system. The noise size and the direction of the noise source of a monitoring point are associated by the utility model in the environmental noise monitoring, and the environmental noise monitoring content and function are greatly expanded so as to facilitate the arbitration and control of environmental noise.

Description

But a kind of environmental noise monitoring device of distinguishing noise source direction

Technical field

The utility model relates to environmental noise monitoring device, but a kind of environmental noise monitoring device of distinguishing noise source direction particularly.

Technical background

Along with the sustainable development of industries such as commercial production, communications and transportation and the increase of urban population, the influence of environmental noise on human class life is serious day by day, noise pollution has become a human current important environmental problem must facing, is big public hazards that influence the human society environment.Numerous in recent years researchers carry out extensive studies from different angles such as the management of neighbourhood noise, improvement, control, planning to it.Environment noise monitoring is the basis that people understand the neighbourhood noise present situation, carry out neighbourhood noise experimental simulation and neighbourhood noise forecasting research, also is the important scientific evidence that environmental administration carries out the neighbourhood noise law enforcement, administers.

Domestic and international famous acoustic instrument company has developed the environmental noise monitoring device of different model, as Denmark B﹠amp; The B﹠amp of K company; The AWA6218S/J type environment noise monitoring system of the NMT1000 type of the 870B type of the Nor-1501 type of K3639 series, Norway Norsonic company, U.S. Larson David company, Beijing popularity company, Hangzhou AIWA.

Divide from the formation of functional module, present environment noise monitoring system constitutes as Fig. 1, according to the difference of major function, can be divided into environment noise monitoring terminal and control center.Wherein environment noise monitoring terminal comprises functional modules such as the on-the-spot demonstration of noise measurement front end, preposition amplification, signal condition, A/D collection and signal Processing, data transmission and noise figure, mainly finishes neighbourhood noise value field monitoring.The control center of environment noise test system comprises that mainly Noise map drafting, statistical study as a result, measurement result are stored in modules such as report generation, control center receives single/noise data that a plurality of environment noise monitoring terminals transmit, and the test result of a plurality of noise monitoring terminals is carried out analysis-by-synthesis and utilization.

During actual the use, environment noise monitoring terminal is placed on carries out environmental noise measurement on the selected noise measurement point, as airport, road, residential quarter or other public domain.The noise data that the noise measurement terminal must measure in time is delivered to the monitoring point noise information control center of environment noise monitoring system by data transmission module (as utilizing advanced public data networks such as GPRS/CDMA), is convenient to carry out environmental Noise Management.Sometimes for understanding the noise profile on certain regional extent more comprehensively, also available a plurality of environment noise monitoring is distributed in eventually through carrying out the synchronous monitoring of noise on the environment noise monitoring point of optimized choice, form the city regional environment noise supervisory system of a networking, utilize Geographic Information System simultaneously, demonstrate the size distribution of area to be monitored noise figure with the form of Noise map intuitively.

All there is a deficiency in the environment noise monitoring system at present: each noise monitoring terminal only adopts single microphone to carry out noise measurement, and the noise figure size at this measuring point place can only be provided, and the source direction information of monitoring point noise can't be provided.

In fact, the size and the source direction of acquisition environment noise monitoring point place noise have great importance for neighbourhood noise arbitration, improvement etc.For example, the measurement point (as residential quarters) that has a plurality of noise sources surrounding enviroment simultaneously, environmental Noise Management person not only needs to understand the noise figure size at noise monitoring point place, more need to understand is that the noise which sound source of its periphery produces has the greatest impact to this noise monitoring spot noise actually, also promptly need to understand noise monitoring point place noise source direction information, so that carry out neighbourhood noise arbitration and noise abatement.

The utility model content

The utility model is at not providing the noise source direction shortcoming in the existing environmental noise monitoring device, but provide a kind of environmental noise monitoring device of distinguishing noise source direction, in the hope of size and the source direction that obtains the measurement point noise simultaneously, be convenient to noise source is accurately located, for the arbitration and the improvement of neighbourhood noise provides foundation.

The utility model adopts following technical scheme for the technical solution problem:

But the environmental noise monitoring device of the utility model distinguishing noise source direction, its design feature are with four performance parameters consistent microphone, i.e. the noise measurement front end of microphone A, microphone B, microphone C and microphone D composing environment noise monitoring system; Described four microphones are pressed the arranged in form of regular hexahedron on four adjacent summits of regular hexahedron, be initial point wherein with microphone A, from microphone A to microphone B, the distance of microphone C, microphone D is the length of side d of regular hexahedron, is that the line of X-axis, microphone A and microphone C is that the line of Y-axis, microphone A and microphone D is a Z axle form right angle coordinate system with the line of microphone A and microphone B.

But the design feature of the environmental noise monitoring device of the utility model distinguishing noise source direction also is: the value of the length of side d of described regular hexahedron is 10mm-40mm.

Compared with the prior art, the utility model beneficial effect is embodied in:

1, the environmental noise monitoring device that provides of the utility model not only can be measured the size of monitoring point neighbourhood noise, and can pick out the noise source direction of environmental monitoring sites simultaneously, real-time interrelated of the noise of environment noise monitoring point size and noise source direction, realized that with an environment noise monitoring point neighbourhood noise value size of monitoring point is measured and the differentiation of noise source direction, greatly expand environment noise monitoring content and function, be convenient to neighbourhood noise arbitration and improvement.

2, adopt the arithmetic mean method of four microphone noise measured values in the neighbourhood noise value size calculating that the utility model provides, can effectively avoid the neighbourhood noise value measuring error that causes unusually owing to certain sensitivity of microphone;

3, the utility model only adopts four microphones that are arranged on adjacent 4 vertex positions of imaginary regular hexahedron, has realized the approximate differentiation of noise source direction, and system hardware constitutes simple, and computation process is simple, clear concept.

Description of drawings

Fig. 1 constitutes synoptic diagram for the environment noise monitoring system;

Fig. 2 is that the front-end architecture synoptic diagram measured in the utility model 4-microphone noise;

But the loop noise monitoring system of Fig. 3 the utility model distinguishing noise source direction constitutes synoptic diagram.

Embodiment

Referring to Fig. 1, with four performance parameters consistent microphone, i.e. the noise measurement front end of microphone A, microphone B, microphone C and microphone D composing environment noise monitoring system; Four microphones are pressed the arranged in form of regular hexahedron on four adjacent summits of regular hexahedron, be initial point wherein with microphone A, from microphone A to microphone B, the distance of microphone C, microphone D is the length of side d of regular hexahedron, the value of length of side d is 10mm-40mm, is that the line of X-axis, microphone A and microphone C is that the line of Y-axis, microphone A and microphone D is a Z axle form right angle coordinate system with the line of microphone A and microphone B.

Be weighted on average with the method for arithmetic mean microphone A, microphone B, microphone C, the measured noise signal of microphone D, obtain the size of noise monitoring point place noise figure the noise measurement front end;

Noise is that the simple harmonic wave by various different frequencies constitutes jointly, and they are all followed the wave propagation theory and propagate forward in the space.The sound intensity is the physical quantity that can represent sound wave spatial transmission direction.By space point along three coordinate axis of rectangular coordinate system (x, y, z) the spatial transmission direction that the sound intensity component of direction just can unique definite sound wave.

Utilize cross-spectrum METHOD FOR SOUND POWER CALCULATION method, but go out the sound intensity component Ix of place, monitoring point along coordinate axis x direction by the noise signal approximate treatment that microphone A and microphone B measure; But go out the sound intensity component Iy of place, monitoring point along coordinate axis y direction by the noise signal approximate treatment that microphone A and microphone C measure; But go out the sound intensity component Iz of place, monitoring point along coordinate axis z direction by the noise signal approximate treatment that microphone A and microphone D measure; Determine the source direction of place, monitoring point noise according to described Ix, Iy, Iz.

In the present embodiment, concrete enforcement is carried out as follows

1, the noise figure P of noise monitoring point place _OSize obtain as follows:

A, the time domain sound pressure signal that utilizes microphone A, B, C, D to measure are respectively p _A(t), p _B(t), p _C(t), p _D(t);

B, above-mentioned four time domain sound pressure signals are carried out frequency, time weighted is handled and the signal effective value calculates respectively, obtain four noise figure: P _A, P _B, P _C, P _D

C, to noise figure P _A, P _B, P _C, P _DCarry out arithmetic mean, obtain the mean value of noise, be i.e. the big or small P of noise monitoring point place noise figure _O

$P_O=\frac{P_A+P_B+P_C+P_D}{4}$

2, distinguishing of noise monitoring point place's noise source direction:

Utilize the measured time domain sound pressure signal of microphone A, microphone B, microphone C, microphone D easily approximate treatment obtain sound intensity component Ix, Iy, Iz along the rectangular coordinate system change in coordinate axis direction;

A, by microphone A and the measured time domain sound pressure signal of microphone B p _A(t), p _B(t) calculate axial sound intensity Ix along rectangular coordinate system x:

$\mathrm{Ix}=\frac{\mathrm{Im}\left[G_{\mathrm{AB}}\left(f\right)\right]}{2\mathrm{\πf\ρd}}$

Wherein: Ix---the sound intensity value that measurement point frequency c is;

G _AB(ω)---the measured time domain sound pressure signal of microphone A, B p _A(t) and p _B(t) cross-power spectrum function, plural number;

Im[]---ask for the computing of complex function imaginary part;

The density of the medium of ρ---conduct acoustic waves, constant.Get 1.293kg/m in the air ³

D---the distance between microphone A, the B, constant;

F---measure the frequency of sound wave;

B, by microphone A and the measured time domain sound pressure signal of microphone C p _A(t), p _C(t) calculate axial sound intensity Iy along rectangular coordinate system x:

$\mathrm{Iy}=\frac{\mathrm{Im}\left[G_{\mathrm{AC}}\left(f\right)\right]}{2\mathrm{\πf\ρd}}$

Wherein: G _AC(f)---the measured time domain sound pressure signal of microphone A, C p _A(t) and p _C(t) cross-power spectrum function, plural number;

C, by microphone A and the measured time domain sound pressure signal of microphone D p _A(t), p _D(t) calculate axial sound intensity Iz along rectangular coordinate system x:

$\mathrm{Iz}=\frac{\mathrm{Im}\left[G_{\mathrm{AD}}\left(f\right)\right]}{2\mathrm{\πf\ρd}}$

Wherein: G _AD(f)---the measured time domain sound pressure signal of microphone A, D p _A(t) and p _D(t) cross-power spectrum function, plural number;

D, can uniquely determine measured propagation of noise direction, can represent that with angle α, β, the γ of itself and coordinate axis computing formula is as follows by the known sound intensity component Ix of size and Orientation, Iy, Iz:

$\cos \mathrm{\α}=\frac{\mathrm{Ix}}{\sqrt{{\mathrm{Ix}}^2+{\mathrm{Iy}}^2+{\mathrm{Iz}}^2}}$

$\cos \mathrm{\β}=\frac{\mathrm{Iy}}{\sqrt{{\mathrm{Ix}}^2+{\mathrm{Iy}}^2+{\mathrm{Iz}}^2}}$

$\cos \mathrm{\γ}=\frac{\mathrm{Iz}}{\sqrt{{\mathrm{Ix}}^2+{\mathrm{Iy}}^2+{\mathrm{Iz}}^2}}.$

Claims (2)

1. but the environmental noise monitoring device of a distinguishing noise source direction is characterized in that the microphone with four performance parameter unanimities, i.e. the noise measurement front end of microphone A, microphone B, microphone C and microphone D composing environment noise monitoring system; Described four microphones are pressed the arranged in form of regular hexahedron on four adjacent summits of regular hexahedron, be initial point wherein with microphone A, from microphone A to microphone B, the distance of microphone C, microphone D is the length of side d of regular hexahedron, is that the line of X-axis, microphone A and microphone C is that the line of Y-axis, microphone A and microphone D is a Z axle form right angle coordinate system with the line of microphone A and microphone B.

2. but the environmental noise monitoring device of distinguishing noise source direction according to claim 1, the value that it is characterized in that the length of side d of described regular hexahedron is 10mm-40mm.

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