CN201233274Y - Sound field testing system in vehicle - Google Patents

Abstract

The utility model provides an in-vehicle sound field testing system, comprising a plurality of acoustic sensors, a signal conditioning circuit, an A/D conversion module, a data collection module and an industrial computer; wherein, the signal output end of the acoustic sensor is connected with the signal input end of the signal conditioning circuit; the signal output end of the signal conditioning circuit is connected with the signal input end of the A/D conversion module; the signal output end of the A/D conversion module is connected with the signal input end of the data collection module; a plurality of acoustic sensors are provided; the industrial computer comprises a data storage module, an on-line measurement module and an offline analysis module, and the data storage module and the on-line measurement module receive data output by the data collection module and the offline analysis module can acquire data from the data storage module.The system can collect multi-point voice-frequency signals simultaneously and make comparison analysis of the voice-frequency signals.

Description

A kind of vehicle interior sound field test macro

Technical field

The utility model relates to a kind of sound field test macro.

Background technology

Automobile plays enormous function as the modern transportation instrument in current society.In recent years, the automobile consumer more and more pays close attention to the sense of hearing comfortableness in the vehicle, and country has also put into effect corresponding automobile noise standard.Therefore, each big automobile vendor adopts various measures one after another, makes great efforts to promote the sense of hearing comfortableness of automobile.

For the conventional acoustic testing tool, as sound meter, audio analyzer, because the restriction of number of channels and function, only can obtain the simple sound field information (sound pressure level or spectrum information) of single test point, but can not analyse in depth, the comparative analysis of several groups of * .wav files more can not be provided the * .wav file of preserving.Yet in most of the cases, we wish to gather simultaneously the sound signal of multiple spot, and on-line measurement each point parameters,acoustic, show nuance, and several roads sound signal can be preserved simultaneously, so that further deeply carry out the off-line comparative analysis of associated arguments.

The utility model content

The purpose of this utility model provides a kind of vehicle interior sound field test macro, and it can gather the sound signal of multiple spot simultaneously, and this sound signal is analyzed.

For achieving the above object, the utility model provides a kind of vehicle interior sound field system, this system comprises sonic transducer, signal conditioning circuit, the A/D modular converter, data acquisition module and industrial computer, the signal output part of described sonic transducer connects the signal input part of signal conditioning circuit, the signal output part of signal conditioning circuit connects the signal input part of A/D modular converter, the signal output part of A/D modular converter connects the signal input part of data acquisition module, wherein, described sonic transducer is a plurality of, described industrial computer comprises data preservation module, on-line measurement module and off-line analysis module, data preserve module and the on-line measurement module receives the data that described data acquisition module is exported, and the off-line analysis module can be preserved from data and be obtained data the module.

The vehicle interior sound field test macro that the utility model provides can be gathered the sound signal of a plurality of points simultaneously, data acquisition module is input to these sound signals the on-line measurement module of industrial computer, for this module sound signal is carried out on-line analysis, or sound signal is kept at data preserves in the module, carry out follow-up further analysis for the off-line analysis module.Compare with existing sound field test macro, the vehicle interior sound field test macro that the utility model provides can be gathered the sound signal of multiple spot simultaneously, and on-line measurement each point parameters,acoustic, show nuance, and several roads sound signal can be preserved simultaneously, so that further deeply carry out the off-line comparative analysis of associated arguments.

Description of drawings

Fig. 1 is the structural representation of the vehicle interior sound field test macro that provides of the utility model;

Fig. 2 is the flow chart of data processing figure of the fft analysis submodule of on-line measurement module;

Fig. 3 is the flow chart of data processing figure of the octave analysis submodule of on-line measurement module;

Fig. 4 is the flow chart of data processing figure of the sound level measurement submodule of on-line measurement module;

Fig. 5 is the flow chart of data processing figure that the frequency response curve of off-line analysis module compares the secondary submodule.

Embodiment

The utility model will be further described below in conjunction with accompanying drawing.

As shown in Figure 1, the vehicle interior sound field test macro that the utility model provides comprises sonic transducer 1, signal conditioning circuit 2, A/D modular converter 3, data acquisition module 4 and industrial computer 5, the signal output part of described sonic transducer 1 connects the signal input part of signal conditioning circuit 2, the signal output part of signal conditioning circuit 2 connects the signal input part of A/D modular converter 3, the signal output part of A/D modular converter 3 connects the signal input part of data acquisition module 4, wherein, described sonic transducer 1 is a plurality of, described industrial computer 5 comprises data preservation module, on-line measurement module and off-line analysis module, data preserve module and the on-line measurement module receives the data that described data acquisition module 4 is exported, the off-line analysis module can be preserved from data and be obtained data the module, data is preserved the data of module acquisition and carries out deep off-line analysis.

Described sonic transducer 1 is for well known to a person skilled in the art sensor, and sonic transducer 1 is a plurality of, is preferably 2-8.A plurality of sonic transducers 1 can be placed on a plurality of positions simultaneously, when carrying out the vehicle interior sound field measurement, can be by the sound-source signal of car audio system outputting standard, sonic transducer is gathered sound pressure signal to the point of being paid close attention to respectively, for example, a plurality of positions such as the position at ear place, two people from seats of driver and VIP, copilot vehicle window position, inside rear view mirror position, dickey seats position, sonic transducer 1 is simultaneously to these station acquisition sound pressure signals.

Described A/D modular converter 3 is used for analog signal conversion is become digital signal, and it can for example be to well known to a person skilled in the art AD974.

Described signal conditioning circuit 2 comprises filtering circuit, buffer circuit and amplifying circuit, and the signal of sonic transducer 1 output filtering, the isolation of buffer circuit and the amplification of amplifying circuit of wave circuit after filtration outputs to afterwards described A/D modular converter 3.Described filtering circuit, buffer circuit and amplifying circuit are for well known to a person skilled in the art circuit.

Described industrial computer 5 has data terminal, described data acquisition module 4 comprises processor, SRAM (static RAM) and Flash (flash memory) storer, described SRAM is connected with described processor with the Flash storer, the signal input part of described processor connects the signal output part of described A/D modular converter 3, the data terminal of the described industrial computer 5 of data termination of processor.Described data preservation module and on-line measurement module receive the data of described data acquisition module 4 outputs from the data terminal of industrial computer 5.

Under the preferable case, described SRAM is two.SRAM plays the effect of buffer memory to the data that collect in circuit, it has two kinds of duties, promptly write data and sense data, use two SRAM, then can all can there be a SRAM to be in the state of reading at any time, the speed of sense data is just fast like this, can satisfy the requirement that high-speed data reads.

Store the program of calling for described processor in the described Flash storer, processor will store into two SRAM from the signal timesharing that described A/D modular converter 3 receives, the data read that will wherein be in then among the SRAM of " reading " state is come out, and is sent to described industrial computer 5.

Described processor can be DSP, single-chip microcomputer, FPGA (field programmable gate array) etc., is preferably FPGA.

Described vehicle interior sound field test macro also comprises interface module 7, and interface module 7 is serially connected in the circuit between data acquisition module 4 and the industrial computer 5, and two data transmission terminals connect the data terminal of processor in the described data acquisition module 4 and the data terminal of industrial computer 5 respectively.Described interface module 7 can be RS-232 interface module or usb interface module, is preferably usb interface module.

Described industrial computer 5 can be computing machine or DSP etc., is preferably computing machine.Described industrial computer 5 comprises data preservation module, on-line measurement module and off-line analysis module.

Described on-line measurement module comprises that FFT (fast fourier transform) analyzes submodule, octave analysis submodule and sound level measurement submodule.Be sent to data acquisition module 4 from described sonic transducer 1 detected multichannel sound pressure signal through signal conditioning circuit 2, A/D modular converter 3, multichannel sound pressure signal after the data acquisition module 4 output conversions is to the fft analysis submodule, as shown in Figure 2, the fft analysis submodule carries out windowing, average and fast fourier transform respectively successively with each road of this multichannel sound pressure signal, and many frequency response curves that obtain after handling are presented in the oscillogram.

As shown in Figure 3, each road of the multichannel sound pressure signal after described octave analysis submodule will be changed is weighted respectively successively, average and third-octave calculation process, and many frequency response curves after handling are presented on display 6 in the oscillogram.

The third-octave bandwidth is a fixed percentage bandwidth, and its frequency bandwidth is the constant percentage of centre frequency always, centre frequency f ₀With bandwidth upper and lower limit cutoff frequency f _hAnd f _lThe pass be:

$f_0=\sqrt{f_h*f_l}$

f _h＝2 ^1/3*f _l

As shown in Figure 4, each road of the multichannel sound pressure signal after described sound level measurement submodule will be changed be weighted successively respectively with average treatment after, carry out SPL and Leq calculation process more respectively.SPL and L _EqComputing formula as follows:

$\mathrm{SPL}=20*\lg \frac{p_e}{p_0}\left(\mathrm{dB}\right)$

$L_{\mathrm{eq}}=10*\lg \left[\frac{1}{t_2-t_1}{\∫}_{t_1}^{t_2}(p^2/p_0^2)\mathrm{dt}\right]$

Wherein p is a sound pressure level, p _eBe the effective value of acoustic pressure to be measured, p ₀Be reference sound pressure, p ₀=2 * 10 ^-5Pa, t ₂With t ₁Difference equal the sampling period.

Show with oscillogram through the sound pressure signal after the SPL calculation process; Through L _EqSound pressure signal after the calculation process is with L _EqThe form of value shows.

Above submodule is to multichannel sound pressure signal individual processing, and the processing of each road sound pressure signal is not influenced mutually.

Each road that described data are preserved the multichannel sound pressure signal after module will be changed saves as the * .wav file that sample frequency is 50KHz, the later follow-up off-line analysis that carries out.This module has general mode, timing mode and automatic mode selective.General mode promptly begins data to be preserved and stops preservation and can directly control by button, can begin at any time to preserve data or stop to preserve data; Timing mode promptly before data are preserved, be set the time span that will preserve data earlier, and data promptly can stop to preserve data after preserving the time span that reaches setting; After the working method of automatic mode was beginning, system began playing standard sound source file, begins to preserve data simultaneously, and the sound source file stops to preserve data when finishing, generate the identical * .wav file of a plurality of sizes.Standard source can be selected 20Hz～20KHz swept-frequency signal and 1KHz pure tone signal.

Described off-line analysis module comprises wave file analysis submodule and wave file comparison sub-module.

Wave file analysis submodule comprises a kind of in the following secondary submodule at least: time domain waveform shows secondary submodule, octave analysis secondary submodule, power spectrum secondary submodule, FFT secondary submodule, total harmonic distortion (THD) secondary submodule, short time discrete Fourier transform (SFFT) secondary submodule and SPL﹠amp; Leq secondary submodule.Function that these secondary submodules are realized and effect are known to those skilled in the art, seldom do description.These secondary submodules adopt the concurrent program structure, can specify by the tab control in the off-line analysis module and select which secondary submodule for use, preserve from described data and import * .wav file the module, just can analyze accordingly, and show.

Wave file comparison sub-module comprises a kind of in the following secondary submodule at least: time domain waveform is relatively secondary submodule, THD﹠amp of secondary submodule, frequency response curve relatively; The THD+N value is the secondary submodule relatively.The wave file analysis program of each secondary submodule adopts the concurrent program structure, and the data processing of many groups wave file is independent of each other, and the computing formula of THD and THD+N is as follows:

$\mathrm{THD}=\frac{\mathrm{\Σ}{P}_{\mathrm{Harmonics}}}{\mathrm{\Σ}{P}_{\mathrm{Total}}}$

$\mathrm{THD}+N=\frac{\mathrm{\Σ}{P}_{\mathrm{Harmonics}}+\mathrm{\Σ}{P}_{\mathrm{Noise}}}{\mathrm{\Σ}{P}_{\mathrm{Total}}}$

∑ P _TotalRepresent total energy value, ∑ P _Harmonic,Represent the harmonic wave total energy value, ∑ P _NoiseExpression noise total energy value.

The flow chart of data processing of the single wave file in the frequency response curve comparison secondary submodule processing multichannel wave file obtains the sampling number X of each analysis as shown in Figure 5; Obtain the sampling number Y of pending wave file; Determine needs round-robin times N, N=X/Y according to X and Y; Read Wave data; Carry out windowing, weighting, average, FFT successively; Output shows.If round-robin number of times+1 equals N, then finish this processing procedure, if be not equal to N, then begin to handle from reading Wave data.

What function that described time domain waveform comparison secondary submodule is realized and effect were known to those skilled in the art is used for multichannel wave file demonstration time domain waveform figure, relatively its oscillogram.

The function of above-mentioned module can be called corresponding program by industrial computer 5 and realize that this program can be stored in the machine readable media.

In order to finish the Presentation Function of above-mentioned various oscillograms, described vehicle interior sound field test macro also comprises display 6, the data input pin of the data presentation output termination display 6 of described industrial computer 5.The sound signal that collects from sonic transducer 1 after the analyzing and processing of the on-line measurement module of industrial computer 5 or off-line analysis module, can show on display 6 with visual chart or digital mode.

The vehicle interior sound field test macro that the utility model provides, the hyperchannel on-line analysis that it provides, the harmony that data are preserved, off-line comparative analysis function can be applied to vehicle interior sound field detect, walkaway, be specially adapted to the Performance Detection of car audio system, can carry out kinetic measurement to the sound field parameters of each position in the car, the difference that finds each position sound field parameters to exist.By adjusting loudspeaker parameter, putting position and angle car audio system is improved in view of the above.This vehicle interior sound field test macro can carry out on-line measurement to the sound field parameters of a plurality of positions in the car simultaneously, possesses the data hold function, and abundant off-line comparative analysis function is provided, and can satisfy the actual demand of vehicle interior sound field analytical work, improves testing efficiency.This test macro also can be applicable to other sound field analytical applications, as walkaway.Each software function module of system all adopts modular design method, makes things convenient for functions of modules upgrading and optimization.Part of data acquisition adopts the USB connected mode, and portable performance is superior, and dispense with outer connecting power is easy to use, and cost is lower.

Claims (7)

1, a kind of vehicle interior sound field test macro, this system comprises sonic transducer (1), signal conditioning circuit (2), A/D modular converter (3), data acquisition module (4) and industrial computer (5), the signal output part of described sonic transducer (1) connects the signal input part of signal conditioning circuit (2), the signal output part of signal conditioning circuit (2) connects the signal input part of A/D modular converter (3), the signal output part of A/D modular converter (3) connects the signal input part of data acquisition module (4), it is characterized in that, described sonic transducer (1) is a plurality of, described industrial computer (5) comprises data preservation module, on-line measurement module and off-line analysis module, data preserve module and the on-line measurement module receives the data that described data acquisition module (4) is exported, and the off-line analysis module can be preserved from data and be obtained data the module.

2, vehicle interior sound field test macro according to claim 1 is characterized in that, described sonic transducer (1) is 2-8.

3, vehicle interior sound field test macro according to claim 1, it is characterized in that, described industrial computer (5) comprises data terminal, described data acquisition module (4) comprises processor, SRAM and Flash storer, described SRAM is connected with described processor with the Flash storer, the signal input part of described processor connects the signal output part of described A/D modular converter (3), the data terminal of the described industrial computer of data termination (5) of processor.

4, vehicle interior sound field test macro according to claim 3 is characterized in that, described SRAM is 2.

5, vehicle interior sound field test macro according to claim 3 is characterized in that, described processor is FPGA.

6, vehicle interior sound field test macro according to claim 3 is characterized in that, this system also comprises interface module (7), and two data transmission terminals of interface module (7) connect the data terminal of described processor and industrial computer (5) respectively.

According to the described vehicle interior sound field test macro of each claim among the claim 1-6, it is characterized in that 7, this vehicle interior sound field test macro also comprises display (6), the data input pin of the data presentation output termination display (6) of described industrial computer (5).

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