CN105025419A - Active noise reduction system and method - Google Patents
Active noise reduction system and method Download PDFInfo
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- CN105025419A CN105025419A CN201410181467.0A CN201410181467A CN105025419A CN 105025419 A CN105025419 A CN 105025419A CN 201410181467 A CN201410181467 A CN 201410181467A CN 105025419 A CN105025419 A CN 105025419A
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Abstract
The invention provides an active noise reduction system and method. The system includes a digital signal processing board, a simulation signal collection and output board, and power supply modules parallelly arranged in a cuboid; the left surface of the cuboid is provided with an input interface 6, an output interface 7, a signal ground interface 9, a housing ground interface 10, a power plug 13, a power supply fuse 12 and a power switch 11; the simulation signal collection and output board includes two paths of simulation ADs and two paths of simulation Das, and is in connection with the input interface 6 and the output interface 7 of the active noise reduction system; the input interface 6 is used for inputting simulation electric signals generated by a sound transducer, and the output interface is used for outputting noise reduction simulation signals generated by the active noise reduction system to external electronic equipment; the digital signal processing board and the simulation signal collection and output board are parallelly arranged, and two ends of the two boards are in connection through two connectors; the digital signal processing board is used for analyzing characteristics of noise signals, and dividing the noise signals into main noise sources and minor noise sources.
Description
Technical field
The present invention relates to noise reduction field, be specifically related to one one kinds of active noise reduction system and method.
Background technology
In work, the life area of reality, common various noise, these noises often cause various injury to the physical and mental health of surrounding people, the production work even affect, destoryed the scene.Therefore, in order to reach the object of noise reduction, usually adopt active noise reduction and passive noise reduction two kinds of methods, and active noise reduction function being exactly produce the reverse sound wave equal with outside noise by noise reduction system, noise being neutralized, thus realizes the effect of noise reduction.
Active noise control using is a kind of active noise control technique based on sound wave coherent superposition principle, proposed in its patent US2043416 by P.Lueg the earliest, its general principle is introduced secondary sound source and is utilized it to send but phase place contrary " antinoise " identical with initial noisc amplitude in sound field, make initial noisc obtain relevant counteracting, thus reach the object of noise suppressed.Compared with the passive noise-reduction method of tradition, Technique of Active Noise Control main advantage is to obtain better low frequency noise reduction with less volume.Along with the raising of people's living standard, low-frequency noise pollution problem is day by day remarkable, and the practical demand of Technique of Active Noise Control is day by day urgent.On the other hand, through the development of last 100 years, especially along with the leap of Digital Signal Processing nearly decades, Technique of Active Noise Control is increasingly mature, and its practicalization is just progressively accelerated.
In order to reach good active noise reduction effect, an outstanding active control system is the basis of whole active noise reduction platform.Early stage active control system mainly lays particular emphasis on the noise and vibration information gathering multiple measurement point, feedback noise reduction system is separated with acquisition system, a large amount of collection point transducers needs to be connected with collecting device by longer analog signal line, both the reliability that unnecessary wiring difficulty again reduces equipment had been added, and the separation of reponse system arranges and further increases whole active noise reduction system and arrange and the difficulty implemented, whole system is seemed dispersion, poor efficiency and unreliable.And make a general survey of the place that active noise reduction techniques generally applies, usually there is site surrounding complexity, difficulty installed by the long line in monitoring point, the features such as Noise Reduction point and monitoring point close together, so the needs that has Gather and input and controls to export, compact, miniaturized, low-power consumption, the active control system of being convenient to multiple spot networking become a reality simultaneously.
Summary of the invention
The object of the invention is to, provide a kind of small size, low-power consumption, Gather and input and control to be output in one, there is the audio frequency active controller of networking function, be specifically related to a kind of active noise reduction system and method.
To achieve these goals, the invention provides a kind of active noise reduction system, described active noise reduction system is for comprising: be positioned at digital signal panel, collection of simulant signal and the output board that cuboid interior parallel lays, some power modules; The left side of described cuboid is arranged input interface 6, output interface 7, signal ground interface 9, shell ground interface 10, attaching plug 13, power safety 12 and mains switch 11;
Described collection of simulant signal and output board comprise two-way and simulate AD and two-way analog D A, and be connected with the input interface 6 of active noise reduction system and output interface 7, described input interface 6 is for inputting the analog electrical signal produced from sound transducer, and described output interface is used for externally electronic equipment and exports the noise reduction analog signal of active noise reduction system generation;
Described digital signal panel lays with collection of simulant signal is parallel with output board, and the two ends of two planks are connected by two contact pins, and is connected with network communication interface by another contact pin; And described digital signal processing module, for analyzing the feature of noise signal, noise signal is divided into Main Noise Sources and secondary noise source; Described collection of simulant signal and output board are used for carrying out digital-to-analogue conversion process to the acoustical signal gathered, and produce digital signal;
Wherein, described digital signal panel (5) comprises: digital filter block and signal compensation processing module;
Described digital filter block comprises some digital filters, the signal of all digital filters parallel processing simultaneously multichannel different frequency bands, and then retains the signal in frequency band, and the signal outside attenuation band, ensures that the frequency response of whole passband is steady;
Described signal compensation processing module, carries out analog to digital conversion for the analog signal that will collect, then obtains the strength information of signal based on the digital signal that analog to digital conversion obtains, and finally the relation of analytic signal numerical value and time obtains the information of signal phase again; Carried out the contrast of intensity and phase place by the signal produced multi-channel filter, and then obtain the analysis result of primary and secondary noise; Finally produce reverse superposed signal according to main noise signal, reverse superposed signal is used for producing the inverse analog signal of telecommunication by D/A modular converter, the inverse analog signal of telecommunication produces reverse air-borne sound signal or reverse mechanical oscillation signal at the transducer that driving is outside, these reverse signals are added on main noise signal, reach the object of noise reduction.
The equipment such as above-mentioned modules, interface are all arranged in a cuboid, the upper surface of described cuboid is heat-dissipating casing 3, and the placement parallel with output board with described collection of simulant signal of this heat-dissipating casing 3, and this heat-dissipating casing 3 left-half arranges a projection, described projection is pure aluminum material, and this projection contacts with output board upper surface with described collection of simulant signal, and then play the heat conduction of casing internal to getting final product outside effect;
Described cuboid lower surface places some power modules;
Described signal ground interface 9 and shell ground interface 10 be respectively used to equipment room signal altogether with housing shroud ground connection;
Attaching plug 13 connects external power source.
Optionally, the left side of above-mentioned cuboid also arranges power safety 12 and mains switch 11;
Described power safety 12 is for the overcurrent protection of external power source; Described mains switch 11 controls the switch of active noise reduction system.
Optionally, above-mentioned digital signal panel is based on the embedded system of OMAPL137 and fpga chip, and this plate is provided with two standard serial ports and a 10M/100M network interface.
Optionally, above-mentioned collection of simulant signal and output board 4 comprise:
Two 16bit and the AD input channel of sample rate 4M/s;
The DA output channel of two 16bit;
And input interface 6 can be arranged to voltage input or electric current input pattern as required.
Optionally, described digital signal panel 5 is connected by the PC104 connector that two are respectively 120 pins with output board 4 with collection of simulant signal, and connects copper posts by 8 and to be fixed on heat-dissipating casing on 3.
In addition, present invention also offers a kind of active denoising method, described method comprises:
Step 101) sonic transducer gathers acoustical signal or vibration signal, and the acoustical signal of collection is converted to the signal of telecommunication;
Step 102) signal of telecommunication of conversion is carried out Digital Signal Processing, by the analysis to digital signal, comprise the spectrum distribution being obtained signal by digital filtering, the intensity distributions of signal is obtained by the Analyzing on Size of numerical value, and then separate Main Noise Sources and secondary noise source according to frequency and intensity region, then the feature of main noise signal, a reverse superposed simulation signal is produced by digital to analog conversion module, this superposed signal frequency is identical with noise signal, phase place is contrary, intensity is equal, carries out reverse noise reduction;
Wherein, the feature of main noise comprises: the frequency of signal and intensity.
Optionally, above-mentioned steps 101) also comprise before:
By some railway digital filters, at different frequency bands, filtering is carried out to noise signal, therefrom analyze and draw the intensity of signal and the phase place change information of signal;
The signal strength signal intensity drawn and phase place change information are carried out unify contrast, and then obtain the signal that in all noise signals, noise contributions is maximum, record the data of all noise signals simultaneously and carry out probability statistics, and then judging in following a period of time, the probability that each noise signal occurs;
Adopt above-mentioned statistical information, noise reduction process is carried out to the noise produced.Compared with prior art, technical advantage of the present invention is: accurate positioning analysis, the signal of different frequency bands can independently be processed, eliminate the interference of irrelevant information, to the whole process record of signal, achieve probability statistical analysis, judge in advance, preliminary treatment, has been completely free of the deficiency of passive process.
Accompanying drawing explanation
Fig. 1-a and 1-b is the audio frequency active controller cut-away view that provides of the embodiment of the present invention and panel figure;
The audio frequency active controller overall appearance figure that Fig. 2 embodiment of the present invention provides.
Accompanying drawing identifies:
1, AC/DC power supply, 2, DC/DC power supply, 3, case body,
4, collection of simulant signal and output board, 5, digital signal panel, 6, Gather and input interface,
7, output interface is controlled, 8, network interface, 9, signal ground binding post,
10, shell ground binding post, 11, mains switch, 12, power safety,
13, attaching plug.
Embodiment
Below in conjunction with drawings and Examples, the present invention is further described.
The invention provides a kind of audio frequency active controller, comprising: by digital signal processing module 5 and collection of simulant signal module 4; Wherein collection of simulant signal module 4 comprises two-way simulation AD and two-way analog D A, and is connected with input interface 6, output interface 7; Digital signal processing module 5 is connected with collection of simulant signal module 4, and is connected with network communication interface 8; Power module 1 and 2 is fixed on heat-dissipating casing 3; Signal ground interface 9 and shell ground interface 10 be respectively used to equipment room signal altogether with housing shroud ground connection; Attaching plug 13 connects external power source; Power safety 12 is for the overcurrent protection of external power source; The switch of mains switch 11 control system.
Above-mentioned digital signal processing module comprises the embedded system that take OMAPL137 as core, and is integrated with a FPGA (EP3CF484), and with two standard serial ports, a 10M/100M network interface; Collection of simulant signal module comprises the AD input channel of two 16bit, sample rate 4M/s, the DA output channel of two 16bit, and meanwhile, in order to meet the dissimilar of input signal source, input can be arranged to voltage input or electric current input pattern as required; The mode that this digital system of audio frequency active controller and analogue system are integrated together can reduce the cost of whole system, and Measurement architecture is set up fast in more convenient scene simultaneously.
Above-mentioned analog signal AD gathers and comprises two-way analog input and two-way modulating output with DA output board 4, and be connected with input interface 6, output interface 7, this by input AD with export that the mode that is integrated together of DA avoids that traditional constrained input cost that making sheet causes respectively increases, reliability reduces, equipment volume greatly and the various disadvantages such as power consumption increase, and can meet the demand of practical application.
Above-mentioned digital signal processing module 5 is connected with collection of simulant signal module 4, and be connected with network communication interface 8, this method network function being integrated into ACTIVE CONTROL electronic system can be realized multiple ACTIVE CONTROL electronic system and be networked by network, and then realizes multiple spot, Long-distance Control.
Optionally, said system also comprises power module 1 and 2, and heat-dissipating casing; And power module 1 and 2 is fixed on heat-dissipating casing 3, the heat that power supply produces can be transmitted to outside by equipment metal shell by this method effectively.
Innovation of the present invention be in, to carry out analogy method process to signal different from usually adopting, adopt digitized processing noise signal, the feature of noise signal can be analyzed accurately, distinguish Main Noise Sources and secondary noise source, can according to the needs of user, process for some special noise signals, due to the distinctive advantage of Digital Signal Processing, can realize signal procesing in time domain and can realize frequency-region signal process again, and simulation process method in the past cannot reach such performance at all.Simultaneously, the present invention also has ability of self-teaching, can according to the analysis result of existing Noise Acquisition data, the noise signal that will occur is predicted, and adjust noise reduction predeterminated target in time, have obvious noise reduction to random noise, these are all that noise reduction in the past sets the function that cannot have.By multi-path digital filter, at different frequency bands, filtering is carried out to noise signal, therefrom analyze the intensity of signal, these data are carried out unified contrast, and then are judged that the effect of those signals is maximum by the phase place change of signal, record the data of all signals simultaneously, and carry out probability statistical analysis, and then judge in following a period of time, the probability that each signal occurs, so that user makes preparation in advance, reach the effect guarded against in advance.
Embodiment
The audio frequency active controller cut-away view developed according to the present invention and panel figure are as shown in Fig. 1-a and 1-b, and its outward appearance as shown in Figure 2.ACTIVE CONTROL electronic system entirety is rectangle body, and shell sizes is: long 200mm, wide 104mm, high 100mm.
Audio frequency active controller is mainly made up of exterior mechanical housing and internal electron board two large divisions, wherein exterior mechanical housing comprises housing 3 and connector and control panel, and Gather and input interface 6, feedback output interface 7, network interface 8, signal ground binding post 9 are all concentrated with chassis ground binding post 10, mains switch 11, power safety 12 and attaching plug 13 and be arranged on panel.
By outer casing bottom four installing hole fixed installations during in-site installation, also can directly be placed on stable table top.Gather and input interface 6 is 4 pin aviation plugs with feedback output interface 7, network interface 8 is 10 pin aviation plugs, attaching plug 13 is 3 pin aviation plugs, power safety 12 is column protective tube, signal ground binding post 9 and chassis ground binding post 10 are bolt copper post, and mains switch 11 is circular key switch.
First external sensor is connected to Gather and input interface 6 during system works (if constant-current source output transducer, then need Gather and input interface 6 to be set to Constant current input end by jumper cap), control the input that output interface 7 is connected to external power amplifier, network interface 8 is connected on standard ethernet switch, network exchange data and control command can be passed through as required, in the place of electromagnetic interference complexity, should by shell by chassis ground binding post 10 the earth, when needing signal altogether with other equipment connections, should by signal ground binding post 9 altogether, attaching plug 13 connects AC220/50Hz alternating current.Above-mentioned interface connects correctly as required, starts mains switch 11 and ACTIVE CONTROL electronic system is started working.
Audio frequency active controller excellent performance, by test, input background noise Vpp<100uV, export background noise Vpp<100uV, obvious crosstalk is not measured between input channel, obvious crosstalk is not measured between output channel, equipment power dissipation <7.3W, A/D sampling significance bit is 13, most high sampling rate 4M/s, output harmonic wave distortion THD<0.1%, maximum detection amount input voltage Vpp (max)=5V, maximum output voltage Vpp (max)=10V, input Simulation scale-up adjustable magnification.
Present invention also offers a kind of active denoising method, described method comprises:
Step 101) sonic transducer gathers acoustical signal or vibration signal, and the acoustical signal of collection is converted to the signal of telecommunication;
Step 102) signal of telecommunication of conversion is carried out Digital Signal Processing, by the analysis to digital signal, comprise the spectrum distribution being obtained signal by digital filtering, the intensity distributions of signal is obtained by the Analyzing on Size of numerical value, and then separate Main Noise Sources and secondary noise source according to frequency and intensity region, then the feature of main noise signal, a reverse superposed simulation signal is produced by digital to analog conversion module, this superposed signal frequency is identical with noise signal, phase place is contrary, intensity is equal, carries out reverse noise reduction;
Wherein, the feature of main noise comprises: the frequency of signal and intensity.
Above-mentioned steps 101) also comprise before:
By some railway digital filters, at different frequency bands, filtering is carried out to noise signal, therefrom analyze and draw the intensity of signal and the phase place change information of signal; The signal strength signal intensity drawn and phase place change information are carried out unify contrast, and then obtain the signal that in all noise signals, noise contributions is maximum, record the data of all noise signals simultaneously and carry out probability statistics, and then judging in following a period of time, the probability that each noise signal occurs; Adopt above-mentioned statistical information, noise reduction process is carried out to the noise produced.
In sum, the invention provides a kind of audio frequency active controller, its purposes is, by gathering acoustical signal or vibration signal, to export corresponding analog control signal, finally reach the object of vibration and noise reducing after carrying out Digital Signal Processing.Whole electronic system volume is little, low in energy consumption, reliable and stable.This system comprises: the system core be made up of digital signal panel 5 and analog signal plate 4; Wherein analog signal plate 4 comprises two-way simulation AD (constant hydraulic source and constant-current source) and two-way analog D A, and is connected with input interface 6, output interface 7; Digital signal panel 5 is connected with output board 4 with collection of simulant signal, and is connected with network communication interface 8; Power module 1 and 2 is fixed on heat-dissipating casing 3; Signal ground interface 9 and shell ground interface 10 be respectively used to equipment room signal altogether with housing shroud ground connection; Attaching plug 13 connects external power source; Power safety 12 is for the overcurrent protection of external power source; The switch of mains switch 11 control system.
In addition to the implementation, all employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop in the protection range of application claims.
Claims (8)
1. an active noise reduction system, is characterized in that, described active noise reduction system comprises: be positioned at digital signal panel (5) that cuboid interior parallel lays, collection of simulant signal and output board (4), some power modules; The left side of described cuboid is arranged input interface (6), output interface (7), signal ground interface (9), shell ground interface (10), attaching plug (13), power safety (12) and mains switch (11);
Described collection of simulant signal and output board comprise two-way and simulate AD and two-way analog D A, and be connected with the input interface (6) of active noise reduction system and output interface (7), described input interface (6) is for inputting the analog electrical signal produced from sound transducer, and described output interface is used for externally electronic equipment and exports the noise reduction analog signal of active noise reduction system generation; Described collection of simulant signal and output board are used for carrying out digital-to-analogue conversion process to the acoustical signal gathered, and produce digital signal;
Described digital signal panel (5) lays with collection of simulant signal is parallel with output board, and the two ends of two planks are connected by contact pin, and is connected with network communication interface by another contact pin; And described digital signal processing module, for analyzing the feature of noise signal, noise signal is divided into Main Noise Sources and secondary noise source;
Wherein, described digital signal panel (5) comprises: digital filter block and signal compensation processing module;
Described digital filter block comprises some digital filters, the signal of all digital filters parallel processing simultaneously multichannel different frequency bands, and then retains the signal in frequency band, and the signal outside attenuation band, ensures that the frequency response of whole passband is steady;
Described signal compensation processing module, carries out analog to digital conversion for the analog signal that will collect, then obtains the strength information of signal based on the digital signal that analog to digital conversion obtains, and finally the relation of analytic signal numerical value and time obtains the information of signal phase again; Carried out the contrast of intensity and phase place by the signal produced multi-channel filter, and then obtain the analysis result of primary and secondary noise; Finally produce reverse superposed signal according to main noise signal.
2. active noise reduction system according to claim 1, is characterized in that, the modules of described active noise reduction system and unit are laid in a cuboid;
The upper surface of described cuboid is heat-dissipating casing (3), and this heat-dissipating casing (3) placement parallel with output board with described collection of simulant signal, and this heat-dissipating casing (3) left-half arranges a projection, described projection is pure aluminum material, and this projection contacts with output board upper surface with described collection of simulant signal, and then play the heat conduction of casing internal to getting final product outside effect;
Described cuboid lower surface places some power modules;
Described signal ground interface (9) and shell ground interface (10) be respectively used to equipment room signal altogether with housing shroud ground connection;
Attaching plug 13 connects external power source.
3. active noise reduction system according to claim 1, is characterized in that, the left side of described cuboid is also arranged power safety (12) and mains switch (11);
Described power safety (12) is for the overcurrent protection of external power source; Described mains switch (11) controls the switch of active noise reduction system.
4. active noise reduction system according to claim 1, is characterized in that, described digital signal panel is based on the embedded system of OMAPL137 and fpga chip, and this plate is provided with two standard serial ports and a 10M/100M network interface.
5. active noise reduction system according to claim 1, is characterized in that, described collection of simulant signal and output board (4) comprise:
Two 16bit and the AD input channel of sample rate 4M/s;
The DA output channel of two 16bit;
And input interface (6) can be arranged to voltage input or electric current input pattern as required.
6. active noise reduction system according to claim 1, is characterized in that,
Described digital signal panel (5) is connected by the PC104 connector that two are respectively 120 pins with output board (4) with collection of simulant signal, and connects copper posts by 8 and to be fixed on heat-dissipating casing on (3).
7. an active denoising method, described method comprises:
Step 101) sonic transducer gathers acoustical signal or vibration signal, and the acoustical signal of collection is converted to the signal of telecommunication;
Step 102) signal of telecommunication of conversion is carried out Digital Signal Processing, by the analysis to digital signal, comprise the spectrum distribution being obtained signal by digital filtering, the intensity distributions of signal is obtained by the Analyzing on Size of numerical value, and then separate Main Noise Sources and secondary noise source according to frequency and intensity region, then according to the feature of main noise signal, a reverse superposed simulation signal is produced by digital to analog conversion module, this superposed signal frequency is identical with noise signal, phase place is contrary, intensity is equal, carries out reverse noise reduction;
Wherein, the feature of main noise comprises: the frequency of signal and intensity.
8. active denoising method according to claim 6, is characterized in that, described step 101) also comprise before:
By some railway digital filters, at different frequency bands, filtering is carried out to noise signal, therefrom analyze and draw the intensity of signal and the phase place change information of signal;
The signal strength signal intensity drawn and phase place change information are carried out unify contrast, and then obtain the signal that in all noise signals, noise contributions is maximum, record the data of all noise signals simultaneously and carry out probability statistics, and then judging in following a period of time, the probability that each noise signal occurs;
Adopt above-mentioned statistical information, noise reduction process is carried out to the noise produced.
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| CN106910492A (en) * | 2017-04-01 | 2017-06-30 | 广州日滨科技发展有限公司 | The noise initiative control method and device of a kind of lift car |
| CN107948831A (en) * | 2017-12-25 | 2018-04-20 | 广州市尊浪电器有限公司 | A kind of sound equipment |
| CN107948872A (en) * | 2017-12-25 | 2018-04-20 | 广州市尊浪电器有限公司 | A kind of WIFI chargings intelligent sound |
| CN108124219A (en) * | 2017-12-25 | 2018-06-05 | 广州市尊浪电器有限公司 | A kind of noise abatement intelligent sound |
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