Noise control device, electrical equipment and noise control method thereof
阅读说明：本技术 一种噪音控制装置、电器设备及其噪音控制方法 (Noise control device, electrical equipment and noise control method thereof ) 是由 周声 王重 刘智亮 张威 肖彪 于 2020-05-18 设计创作，主要内容包括：本发明公开了一种噪音控制装置、电器设备及其噪音控制方法,该装置包括：第一采集单元,采集电器设备发出的第一噪声信号,以第一噪声信号所在的声场为初级声场；主动降噪单元,根据电器设备发出的第一噪声信号生成第二噪声信号,以第二噪声信号所在的声场为次级声场；并控制初级声场和次级声场相叠加；第二采集单元,采集初级声场和次级声场相叠加所产生的误差噪声信号；主动降噪单元,还根据初级声场和次级声场相叠加所产生的误差噪声信号,调节次级声场；并控制初级声场和调节后的次级声场相叠加。本发明的方案,可以解决对电器设备的主动降噪方式不能拓展降噪频率段而存在降噪效果不好的问题,达到提升对电器设备的降噪效果的效果。(The invention discloses a noise control device, electrical equipment and a noise control method thereof, wherein the device comprises: the first acquisition unit is used for acquiring a first noise signal sent by electrical equipment, and a sound field where the first noise signal is located is taken as a primary sound field; the active noise reduction unit is used for generating a second noise signal according to a first noise signal sent by the electrical equipment, and a sound field where the second noise signal is located is taken as a secondary sound field; and controlling the primary sound field and the secondary sound field to be superposed; the second acquisition unit is used for acquiring an error noise signal generated by superposition of the primary sound field and the secondary sound field; the active noise reduction unit is used for adjusting a secondary sound field according to an error noise signal generated by superposition of the primary sound field and the secondary sound field; and controlling the primary sound field and the adjusted secondary sound field to be superposed. The scheme of the invention can solve the problem that the noise reduction effect is poor because the active noise reduction mode of the electrical equipment cannot expand the noise reduction frequency band, and achieves the effect of improving the noise reduction effect of the electrical equipment.)
1. A noise control apparatus, comprising: the device comprises a first acquisition unit, a second acquisition unit and an active noise reduction unit; wherein the content of the first and second substances,
the first acquisition unit is used for acquiring a first noise signal sent by the electrical equipment, and a sound field where the first noise signal is located is taken as a primary sound field;
the active noise reduction unit is used for generating a second noise signal according to a first noise signal sent by the electrical equipment, and a sound field where the second noise signal is located is taken as a secondary sound field; and controlling the primary sound field and the secondary sound field to be superposed;
the second acquisition unit is used for acquiring an error noise signal generated by superposition of the primary sound field and the secondary sound field;
the active noise reduction unit is also used for adjusting a secondary sound field according to an error noise signal generated by superposition of the primary sound field and the secondary sound field; and controlling the primary sound field and the adjusted secondary sound field to be superposed.
2. The noise control device of claim 1, wherein the active noise reduction unit comprises: a control unit and a sound generating unit; wherein the content of the first and second substances,
the active noise reduction unit generates a second noise signal according to a first noise signal sent by the electrical equipment, and the active noise reduction unit comprises:
the control unit is used for generating a noise control signal of a primary sound field according to a first noise signal sent by the electrical equipment;
a sound generating unit for generating a second noise signal according to a noise control signal of the primary sound field;
and/or the presence of a gas in the gas,
the active noise reduction unit controls the superposition of a primary sound field and a secondary sound field, and comprises the following steps:
the primary sound field is controlled to emit sinusoidal sound signals in a first direction, and the secondary sound field is controlled to emit sinusoidal sound signals in a second direction, wherein the first direction is opposite to the second direction in waveform propagation direction.
3. The noise control device of claim 2, wherein the active noise reduction unit further comprises: a filtering unit;
the filtering unit is used for carrying out first filtering processing on a first noise signal sent by the electrical equipment and acquired by the first acquisition unit; and/or the presence of a gas in the gas,
and the filtering unit is also used for carrying out second filtering processing on an error noise signal generated by superposition of the primary sound field and the secondary sound field acquired by the second acquisition unit.
4. The noise control device according to claim 2 or 3, wherein the control unit generates the noise control signal of the primary sound field according to a first noise signal emitted from the electric appliance, including:
after a first noise signal emitted by electrical equipment is processed by a feedforward controller, a corresponding control signal is generated, a loudspeaker is driven to output a sound signal corresponding to the control signal to generate a secondary sound field, and then a sound wave signal of the secondary sound field is superposed with an original sound wave signal of a primary sound field; and adjusting the intensity of the secondary sound source signal according to a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm by detecting residual noise formed by superposition of the primary sound field and the secondary sound field.
5. The noise control device according to any one of claims 1 to 3, wherein the first collection unit includes: a first microphone; a second acquisition unit comprising: a second microphone; and a first microphone and/or a second microphone disposed at an intermediate position of the primary sound field and the secondary sound field.
6. An electrical device, comprising: the noise control device according to any one of claims 1 to 5.
7. A noise control method of an electric appliance according to claim 6, comprising:
collecting a first noise signal sent by electrical equipment, and taking a sound field where the first noise signal is located as a primary sound field;
generating a second noise signal according to the first noise signal sent by the electrical equipment, wherein a sound field where the second noise signal is located is taken as a secondary sound field; and controlling the primary sound field and the secondary sound field to be superposed;
acquiring an error noise signal generated by superposition of a primary sound field and a secondary sound field;
adjusting the secondary sound field according to an error noise signal generated by the superposition of the primary sound field and the secondary sound field; and controlling the primary sound field and the adjusted secondary sound field to be superposed.
8. The noise control method of an electric appliance according to claim 7, wherein,
generating a second noise signal according to a first noise signal emitted by the electrical equipment, comprising:
generating a noise control signal of a primary sound field according to a first noise signal sent by electrical equipment;
generating a second noise signal according to a noise control signal of the primary sound field;
and/or the presence of a gas in the gas,
controlling the superposition of the primary sound field and the secondary sound field, including:
the primary sound field is controlled to emit sinusoidal sound signals in a first direction, and the secondary sound field is controlled to emit sinusoidal sound signals in a second direction, wherein the first direction is opposite to the second direction in waveform propagation direction.
9. The noise control method of an electric appliance according to claim 8, further comprising:
performing first filtering processing on a first noise signal sent by the electrical equipment and acquired by a first acquisition unit; and/or the presence of a gas in the gas,
and carrying out second filtering processing on an error noise signal generated by superposition of the primary sound field and the secondary sound field acquired by the second acquisition unit.
10. The noise control method of an electric appliance according to claim 8 or 9, wherein generating the noise control signal of the primary sound field based on the first noise signal emitted from the electric appliance comprises:
after a first noise signal emitted by electrical equipment is processed by a feedforward controller, a corresponding control signal is generated, a loudspeaker is driven to output a sound signal corresponding to the control signal to generate a secondary sound field, and then a sound wave signal of the secondary sound field is superposed with an original sound wave signal of a primary sound field; and adjusting the intensity of the secondary sound source signal according to a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm by detecting residual noise formed by superposition of the primary sound field and the secondary sound field.
Technical Field
The invention belongs to the technical field of household appliances, and particularly relates to a noise control device, an electric appliance (especially a range hood) and a noise control method thereof, in particular to an active noise reduction control device of a range hood, a range hood and an active noise reduction control method thereof.
Background
Noise pollution is a very concerned environmental problem all over the world, general noise interference can influence normal work and life of people, and the high-noise environment can cause serious harm to the hearing and physical and mental health of people in long-term life. Conventional noise control techniques may include sound absorption treatment, sound insulation treatment, use of mufflers, isolation of vibrations, damping, etc., referred to as "passive" noise control. However, the passive noise control method is effective for middle and high frequency noise, and has little control effect for low frequency noise. A new technique, active noise control, is then introduced. Active noise control is the leading research direction in the field of acoustic and vibration control, and its basic principle is to superpose artificially generated sound wave or vibration wave with the sound wave or vibration wave to be controlled to weaken or strengthen the wave field power or change the wave field distribution.
In addition, the domestic noise reduction consciousness has been gradually raised, and the necessity of active noise reduction is not neglected from mobile phone manufacturers, earphones, electrical appliance manufacturers, industries, manufacturing industries and other industries working under the noise environment. The difficulties of the active noise reduction control flow mainly include: on one hand, the knowledge range related to active noise reduction is wide and deep, and related knowledge in the fields of acoustic engineering and automatic control needs to be thoroughly mastered and combined with software and hardware development, so that a module is finally realized. The active noise reduction earphone needs to have wide understanding and cognition on structural mechanics and an acoustic cavity structure; and for the overall noise reduction solution of the household appliance, professional acoustic measurement, NVH engineering knowledge and actual engineering experience must be combined. On the other hand, the active noise reduction technology is simple in principle, and actually has very precise requirements on the time control of sound waves; if the delay is not well controlled, it is likely that the noise will be enhanced. In general, the noise reduction algorithm has a high barrier, and at least, the problem that the noise reduction effect is not good because the active noise reduction mode of the electrical equipment cannot expand the noise reduction frequency band exists.
The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.
Disclosure of Invention
The invention aims to provide a noise control device, electrical equipment and a noise control method thereof aiming at the defects, so as to solve the problem that the active noise reduction mode of the electrical equipment cannot expand the noise reduction frequency band and has poor noise reduction effect, and achieve the effect of improving the noise reduction effect of the electrical equipment.
The invention provides a noise control device, comprising: the device comprises a first acquisition unit, a second acquisition unit and an active noise reduction unit; the first acquisition unit is used for acquiring a first noise signal sent by electrical equipment, and a sound field where the first noise signal is located is a primary sound field; the active noise reduction unit is used for generating a second noise signal according to a first noise signal sent by the electrical equipment, and a sound field where the second noise signal is located is taken as a secondary sound field; and controlling the primary sound field and the secondary sound field to be superposed; the second acquisition unit is used for acquiring an error noise signal generated by superposition of the primary sound field and the secondary sound field; the active noise reduction unit is also used for adjusting a secondary sound field according to an error noise signal generated by superposition of the primary sound field and the secondary sound field; and controlling the primary sound field and the adjusted secondary sound field to be superposed.
Optionally, the active noise reduction unit includes: a control unit and a sound generating unit; wherein, the unit of making an uproar falls in initiative generates the second noise signal according to the first noise signal that electrical equipment sent, includes: the control unit is used for generating a noise control signal of a primary sound field according to a first noise signal sent by the electrical equipment; a sound generating unit for generating a second noise signal according to a noise control signal of the primary sound field; and/or the active noise reduction unit controls the superposition of the primary sound field and the secondary sound field, and comprises the following steps: the primary sound field is controlled to emit sinusoidal sound signals in a first direction, and the secondary sound field is controlled to emit sinusoidal sound signals in a second direction, wherein the first direction is opposite to the second direction in waveform propagation direction.
Optionally, the active noise reduction unit further includes: a filtering unit; the filtering unit is used for carrying out first filtering processing on a first noise signal sent by the electrical equipment and acquired by the first acquisition unit; and/or the filtering unit is further used for carrying out second filtering processing on an error noise signal generated by superposition of the primary sound field and the secondary sound field acquired by the second acquisition unit.
Optionally, the control unit generates a noise control signal of the primary sound field according to a first noise signal emitted by the electrical device, and includes: after a first noise signal emitted by electrical equipment is processed by a feedforward controller, a corresponding control signal is generated, a loudspeaker is driven to output a sound signal corresponding to the control signal to generate a secondary sound field, and then a sound wave signal of the secondary sound field is superposed with an original sound wave signal of a primary sound field; and adjusting the intensity of the secondary sound source signal according to a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm by detecting residual noise formed by superposition of the primary sound field and the secondary sound field.
Optionally, the first acquisition unit comprises: a first microphone; a second acquisition unit comprising: a second microphone; and a first microphone and/or a second microphone disposed at an intermediate position of the primary sound field and the secondary sound field.
In accordance with another aspect of the present invention, there is provided an electrical apparatus, including: the noise control device described above.
In another aspect, the present invention provides a noise control method for an electrical device, including: collecting a first noise signal sent by electrical equipment, and taking a sound field where the first noise signal is located as a primary sound field; generating a second noise signal according to the first noise signal sent by the electrical equipment, wherein a sound field where the second noise signal is located is taken as a secondary sound field; and controlling the primary sound field and the secondary sound field to be superposed; acquiring an error noise signal generated by superposition of a primary sound field and a secondary sound field; adjusting the secondary sound field according to an error noise signal generated by the superposition of the primary sound field and the secondary sound field; and controlling the primary sound field and the adjusted secondary sound field to be superposed.
Optionally, wherein the generating a second noise signal according to a first noise signal emitted by an electrical device includes: generating a noise control signal of a primary sound field according to a first noise signal sent by electrical equipment; generating a second noise signal according to a noise control signal of the primary sound field; and/or, controlling the superposition of the primary sound field and the secondary sound field, including: the primary sound field is controlled to emit sinusoidal sound signals in a first direction, and the secondary sound field is controlled to emit sinusoidal sound signals in a second direction, wherein the first direction is opposite to the second direction in waveform propagation direction.
Optionally, the method further comprises: performing first filtering processing on a first noise signal sent by the electrical equipment and acquired by a first acquisition unit; and/or carrying out second filtering processing on an error noise signal generated by superposition of the primary sound field and the secondary sound field acquired by the second acquisition unit.
Optionally, generating a noise control signal of the primary sound field according to the first noise signal emitted by the electrical device includes: after a first noise signal emitted by electrical equipment is processed by a feedforward controller, a corresponding control signal is generated, a loudspeaker is driven to output a sound signal corresponding to the control signal to generate a secondary sound field, and then a sound wave signal of the secondary sound field is superposed with an original sound wave signal of a primary sound field; and adjusting the intensity of the secondary sound source signal according to a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm by detecting residual noise formed by superposition of the primary sound field and the secondary sound field.
According to the scheme, the noise which is generated by the active noise reduction device according to the primary noise generated by the primary sound field and is used for actively reducing the noise of the primary noise is secondary noise, and the secondary noise is used for performing sound wave cancellation processing on the primary noise, so that the noise cancellation in the stereo sound field is realized, and the active noise reduction effect on electrical equipment such as a range hood can be improved.
Furthermore, according to the scheme of the invention, the noise reduction platform, namely the active noise reduction device, is mounted, after the collected noise of the range hood, the secondary sound source is controlled to generate opposite noise according to the noise of the range hood and send out sound waves with the opposite noise to offset the sound waves of the noise of the range hood, so that the active noise reduction treatment of the range hood is realized, and the active noise reduction effect can be ensured.
Further, according to the scheme of the invention, after the collected noise of the range hood, the secondary sound source is controlled to generate opposite noise according to the noise of the range hood and emit sound waves of the opposite noise to counteract the sound waves of the noise of the range hood, and then an error signal formed by superposition of the noise of the range hood and the opposite noise is further detected and the signal intensity of the opposite noise is adjusted according to the error signal, so that the noise reduction effect is optimal.
Therefore, according to the scheme of the invention, by arranging the active noise reduction device, the noise emitted by the electrical equipment needing noise reduction is taken as primary noise, the noise generated by the active noise reduction device according to the primary noise generated by the primary sound field and used for actively reducing the noise of the primary noise is taken as secondary noise, and the sound wave cancellation processing is carried out on the primary noise by utilizing the secondary noise, so that the problem of poor noise reduction effect caused by the fact that the active noise reduction mode of the electrical equipment cannot expand the noise reduction frequency band is solved, and the effect of improving the noise reduction effect of the electrical equipment is achieved; especially, the problem that the noise reduction effect is not good due to the fact that the noise reduction frequency section cannot be expanded in an active noise reduction mode of the range hood is solved, and the effect of improving the noise reduction effect of the range hood is achieved.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
FIG. 1 is a schematic structural diagram of a noise control device according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an embodiment of a feedforward active noise reduction system structure of an electrical apparatus (e.g., a range hood) according to the present invention;
FIG. 3 is a schematic structural diagram of an embodiment of a design layout of a three-dimensional active noise reduction structure of an electrical apparatus (e.g., a range hood) according to the present invention;
FIG. 4 is a schematic diagram of an embodiment of an FXLMS algorithm block diagram of an electrical appliance (e.g., range hood) of the present invention;
FIG. 5 is a schematic flow chart illustrating an embodiment of an active noise reduction process of an electrical device (e.g., range hood) according to the present invention;
FIG. 6 is a flowchart illustrating a noise control method according to an embodiment of the present invention;
fig. 7 is a flowchart illustrating an embodiment of generating a second noise signal according to a first noise signal emitted by an electrical device in the method of the present invention.
The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:
1-a primary sound source; 2-a secondary sound source; 3-microphone.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
According to an embodiment of the present invention, there is provided a noise control apparatus. Referring to fig. 1, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The noise control device is an active noise reduction device, and can be applied to electrical equipment needing noise reduction treatment, such as a range hood and the like. The noise control apparatus may include: the device comprises a first acquisition unit, a second acquisition unit and an active noise reduction unit. The first acquisition unit may be connected to a first input terminal of the active noise reduction unit, and the second acquisition unit may be connected to a second input terminal of the active noise reduction unit.
Specifically, the first collecting unit, such as the first microphone, may specifically be a reference microphone, may be disposed on an electrical apparatus such as a range hood, and may also be disposed at any suitable position near the range hood where noise of the range hood can be collected, and may be configured to collect a first noise signal sent by the electrical apparatus, and a sound field where the first noise signal is located is a primary sound field or a primary sound source.
Specifically, the active noise reduction unit may be configured to generate a second noise signal according to a first noise signal emitted by the electrical device, and use a sound field in which the second noise signal is located as a secondary sound field or a primary sound source; and controlling the primary sound field and the secondary sound field to be superposed so as to realize mutual cancellation of sound wave signals of the primary sound field and the secondary sound field. The arrangement of the propagation direction of the sound wave signal of the secondary sound field and the propagation direction of the sound wave signal of the primary sound field can enable the sound wave signal of the primary sound field and the sound wave signal of the secondary sound field to cancel each other when the primary sound field and the secondary sound field are superposed. For example: the direction of propagation of the acoustic signal of the secondary sound field may be opposite to the direction of propagation of the acoustic signal of the primary sound field.
Specifically, the second collecting unit, such as the second microphone, which may be specifically an error microphone, may be disposed on the active noise reduction unit, or may be disposed at any suitable position near the active noise reduction unit, where the position can collect an error noise signal generated by the superposition of the primary sound field and the secondary sound field, and the position can be used to collect an error noise signal generated by the superposition of the primary sound field and the secondary sound field.
Specifically, the active noise reduction unit may be further configured to adjust the secondary sound field, such as adjusting the intensity of the secondary sound field, according to an error noise signal generated by superimposing the primary sound field and the secondary sound field; and controlling the primary sound field and the adjusted secondary sound field to be superposed so as to realize mutual cancellation of sound wave signals of the primary sound field and the adjusted secondary sound field. Furthermore, the second acquisition unit can continuously acquire error noise signals generated by superposition of the primary sound field and the adjusted secondary sound field, and the first noise emitted by the electrical equipment is subjected to active noise reduction treatment in a circulating mode in sequence, so that the accuracy and reliability of the active noise reduction treatment of the first noise emitted by the electrical equipment can be improved, and the efficiency and effect of the active noise reduction treatment of the electrical equipment can be improved.
For example: by refining an active noise reduction core control system and a basic algorithm, noise cancellation in a stereo field is utilized, and the problem of larger noise caused by sound wave superposition is avoided, so that the noise of electrical equipment such as a range hood in a preset three-dimensional space is obviously reduced. If the electrical equipment is a range hood, the sound information of the range hood is called a reference signal. The reference signal is sent to a feed-forward controller, after being processed by the controller, a corresponding control signal is generated, the loudspeaker is driven to output the sound signal to generate a secondary sound field, and then the secondary sound field is superposed with an original sound wave signal transmitted in a physical way, an error microphone detects an error signal formed by superposition of the primary sound field and the secondary sound field and sends the error signal to the controller, and the controller adjusts the intensity of the secondary sound source signal according to a specific algorithm. The verification proves that the noise of the range hood is relatively high initially, after the noise reduction platform is installed, the primary sound source 1 (such as collected noise of the range hood) sends out a noise signal, the control program sends out an instruction, the secondary sound source 2 (opposite noise generated by the system through an algorithm) sends out another sound wave to offset, and the average reduction is 10db after the system is used.
Therefore, the secondary sound field is generated by utilizing the primary sound field of the noise of the electrical equipment, the primary sound field and the secondary sound field are superposed to cancel the noise in the stereo field, and the noise error generated by superposing the primary sound field and the secondary sound field is utilized to adjust the secondary sound field, so that the phenomenon that the sound waves are superposed to cause larger noise can be avoided, the noise of the electrical equipment such as a range hood in a preset three-dimensional space is obviously reduced, and the active noise reduction effect of the electrical equipment such as the range hood is improved.
In an alternative example, the active noise reduction unit may include: a control unit and a sound production unit. The first acquisition unit may be connected to a first input of the control unit, the second acquisition unit may be connected to a second input of the control unit, and an output of the control unit is connected to the sound emitting unit.
Optionally, the active noise reduction unit generates a second noise signal according to a first noise signal sent by the electrical device, and may include: the control unit, such as a DSP controller, may be adapted to generate a noise control signal of the primary sound field based on the first noise signal emitted by the electrical device. Furthermore, the sound generating unit, such as a loudspeaker, may be configured to generate a second noise signal based on the noise control signal of the primary sound field, with the sound field in which the second noise signal is located being the secondary sound field or the primary sound source.
For example: an active noise reduction control scheme based on a range hood platform is designed by utilizing three core technical points of a feedforward active noise control system platform built by a DSP, structural design in a three-dimensional space, a self-adaptive algorithm and the like, and the scheme is simple, reliable, good in stability and good in control effect. The noise signal is fed back to the controller through the reference microphone, the residual noise is fed back through the error microphone, and the secondary sound source signal is sent out through the loudspeaker. Its advantage is that the microphone can receive the pure noise of the kitchen ventilator, so the system is an open loop, will not cause any closed loop oscillation and squeal, therefore can debug the circuit independently, make the effect of making an uproar reach the best. The structural design considers the superposition of sound waves and is determined through multiple experiments at multiple points. In the scheme of the invention, a closed type tool is used as an experiment platform in an experiment to simulate a three-dimensional space in a range hood; the hardware equipment of the research experiment platform is added with a new chip, and the hardware module is updated, so that the whole experiment platform is more specialized and precise, and is matched with higher experiment requirements.
Therefore, the control unit and the sound production unit generate a secondary sound field based on the noise emitted by the electrical equipment to perform sound wave cancellation on the primary sound field of the electrical equipment, active noise reduction on the noise of the electrical equipment is realized, and the reliability and adjustability of noise reduction processing can be improved.
More optionally, the generating, by the control unit, a noise control signal of the primary sound field according to the first noise signal emitted by the electrical device may include: the control unit, such as a DSP controller, enables a first noise signal emitted by the electrical equipment to be processed by the feedforward controller to generate a corresponding control signal, drives the loudspeaker to output a sound signal corresponding to the control signal to generate a secondary sound field, and further superposes the sound wave signal of the secondary sound field and the original sound wave signal of the primary sound field; and adjusting the intensity of the secondary sound source signal according to a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm by detecting residual noise formed by superposition of the primary sound field and the secondary sound field. Specifically, the reference signal is collected by a reference microphone and sent to a feed-forward controller, the reference signal is processed by the controller to generate a corresponding control signal, a loudspeaker is driven to output the sound signal to generate a secondary sound field, the secondary sound field is further superposed with an original sound wave signal actually sent through a physical path, an error microphone detects residual noise (error signal) formed by superposition of a primary sound field and the secondary sound field and sends the residual noise (error signal) to the controller, and the controller adjusts the intensity of the secondary sound source signal according to a filtering algorithm, a variable step size algorithm and/or a least mean square algorithm.
For example: the FXLMS algorithm is a basic algorithm for synthesizing and applying an FIR filter structure and a Least Mean Square (LMS) algorithm, so that a control system is simple and stable, and is widely used in self-adaptive vibration noise control and is also used in an active noise reduction technology. The LMS algorithm is an acoustic wave cancellation algorithm, and the FXLMS algorithm is added with a filter on the basis of the LMS algorithm. In the scheme of the invention, a filtering algorithm, a variable step length algorithm and the like are added, so that more controllable factors are provided for the active noise reduction process.
Therefore, the noise control signal of the primary sound field can be better controlled by processing the first noise signal sent by the electrical equipment by using a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm, and the cancellation of the first noise signal by the second noise signal generated based on the noise control signal can be better controlled.
Optionally, the controlling the primary sound field and the secondary sound field to be superimposed by the active noise reduction unit may include: the primary sound field is controlled to emit sinusoidal sound signals in a first direction, and the secondary sound field is controlled to emit sinusoidal sound signals in a second direction, wherein the first direction is opposite to the second direction in waveform propagation direction.
For example: in the initial active noise reduction experiment, a CCS programming and hardware equipment, a feedforward experiment platform (such as a feedforward active noise control system) are used to implement a sound wave cancellation experiment, such as a sine wave cancellation experiment in the previous period: firstly, a software platform writes a program to enable a feedforward experiment platform to send out a sine sound wave signal and send out a reverse sine sound wave to offset.
Therefore, by controlling the primary sound field and the secondary sound field to send out sinusoidal sound wave signals in opposite directions, the sound wave mutual cancellation effect is good, and the active noise reduction effect is favorably improved.
In a further optional example, the active noise reduction unit may further include: and a filtering unit. And the filtering unit can be matched with the first acquisition unit and/or the second acquisition unit. The filtering unit can select an FIR filter.
The filtering unit can be used for performing first filtering processing on a first noise signal sent by the electrical equipment and acquired by the first acquisition unit; and/or the filtering unit can be further used for carrying out second filtering processing on an error noise signal generated by superposition of the primary sound field and the secondary sound field acquired by the second acquisition unit.
From this, through setting up the filtering unit, can carry out the filtering to the impurity signal in first noise signal and/or the error noise signal, be favorable to promoting the accurate nature that the control unit handled first noise signal and/or error noise signal.
In an alternative example, the first acquisition unit may include: a first microphone. A second acquisition unit, which may include: a second microphone. And a first microphone and/or a second microphone disposed at an intermediate position of the primary sound field and the secondary sound field.
For example: the
Therefore, the position of the microphone is set, so that the accuracy of noise collection is improved, and the accuracy of active noise reduction treatment is improved.
Through a large number of tests, the technical scheme of the invention is adopted, the noise which is generated by the active noise reduction device according to the primary noise generated by the primary sound field and can be used for actively reducing the noise of the primary noise is secondary noise, and the secondary noise is used for carrying out sound wave cancellation treatment on the primary noise, so that the noise cancellation in the stereo sound field is realized, and the active noise reduction effect on electrical equipment such as a range hood can be improved.
With the trend development of the range hood towards large suction force and large air volume, the near-suction range hood is widely popularized in the market and is favored by the majority of users. However, the noise of the near-suction range hood is larger than that of the European machine, and noise control is more needed; in the near-suction range hood, the fan moves downwards, so that the space between the fan and the air inlet is narrower compared with a European-style range hood, and the passive noise reduction has high requirement on the space volume, so that the active noise reduction mode is very necessary to offset the medium-low frequency noise in the near-suction range hood. The existing active noise elimination technology is only limited to the active noise reduction technology of a single channel, for example, some range hoods with active noise reduction devices adopt the active noise elimination technology of the single channel. Although the range hood with the active noise reduction device can effectively reduce noise and does not sacrifice the smoke exhaust air quantity of the range hood in the noise reduction process, the noise reduction frequency section cannot be expanded, so that the design of the active noise reduction process of the range hood needs to be further improved.
According to the embodiment of the invention, an electrical appliance corresponding to the noise control device is also provided. The electric device may include: the noise control device described above.
In an optional embodiment, the scheme of the invention provides an active noise reduction control method of a range hood and an active noise reduction device for reducing low-frequency noise in the range hood by utilizing DSP software and hardware development, three-dimensional space structure design and a filtering algorithm, and the active noise reduction control flow is realized by mainly utilizing the DSP software and hardware, the three-dimensional space structure design and the improved algorithm. The CCS software platform comprises an anti-phase program and a sine wave cancellation program, wherein the anti-phase program is mainly used for identifying the characteristic frequency of noise and outputting a value opposite to a sampling value or delaying to output a value opposite to the sampling value; the sine wave cancellation program can be decomposed into a combination of a plurality of sine signals based on all signals, the noise characteristic frequency is identified by sampling the reference signal, and then a sine wave signal in the direction of the noise characteristic frequency is output through the anti-phase program. An active noise reduction control scheme based on the range hood platform is designed by utilizing three core technical points such as a feedforward active noise control system platform built by a DSP, a structural design in a three-dimensional space, a self-adaptive algorithm and the like, and the scheme is simple, reliable, good in stability and good in control effect.
Compared with the common single-channel active noise elimination technology, the scheme of the invention refines an active noise reduction core control system and a basic algorithm, researches the problem of noise cancellation in a stereo field and how to avoid the problem of larger noise caused by sound wave superposition, and obviously reduces the noise of the range hood in a preset three-dimensional space.
In an alternative embodiment, a specific implementation process of the scheme of the present invention can be exemplarily described with reference to the examples shown in fig. 2 to 5.
Fig. 2 shows a typical structure of a feedforward active noise reduction system. As shown in fig. 2, in the feedforward active noise reduction system, a first noise signal (e.g., a noise signal) is used as a main noise signal, and is input to a first input terminal of a feedforward controller after being picked up by a first microphone (e.g., a reference microphone). The second noise signal (e.g., residual noise) is used as a secondary noise signal, and is inputted to the second input terminal of the feedforward controller after being picked up by the second microphone (e.g., error microphone). The feed-forward controller processes the pickup signals of the first noise signal and the second noise signal and outputs a secondary sound source to the loudspeaker.
The feedforward active noise reduction system uses a feedforward active noise control system, which is also called an open loop noise control system, and its typical structure is shown in fig. 2. Such systems require acoustic information of the noise signal being controlled (primary sound field), often referred to as reference signal. The reference signal is collected by a reference microphone and sent to a feed-forward controller, a corresponding control signal is generated after the reference signal is processed by the controller, a loudspeaker is driven to output the sound signal to generate a secondary sound field, the secondary sound field is superposed with an original sound wave signal transmitted in a physical way, an error microphone detects residual noise (error signal) formed by superposition of the primary sound field and the secondary sound field and sends the residual noise to the controller, and the controller adjusts the intensity of the secondary sound source signal according to a specific algorithm.
Fig. 3 is a design layout of an active noise reduction structure in three-dimensional space. As shown in fig. 3, in the three-dimensional space active noise reduction structure, a
Fig. 4 is a block diagram of the FXLMS algorithm (i.e., the X-filter least mean square algorithm). As shown in fig. 4, the input signal X (n) is processed by the first processing a (n) to obtain a first processed signal d (n), processed by the second processing b (n) to obtain a second processed signal y (n), and processed by the third processing f (n) to obtain a third processed signal X' (n). The second processed signal Y (n) is processed by the fourth process C (n) and then the fourth processed signal is outputted. The first processed signal D (n) and the second processed signal are superposed to form an output signal E (n).
Further, the output signal e (n) is fed back to the LMS process (i.e. the least mean square algorithm, specifically, the acoustic wave cancellation algorithm), and the third processed signal X' (n) and the output signal e (n) are subjected to the LMS process to obtain a fifth processed signal, which is fed back to the second process b (n). The second processing b (n) processes the input signal x (n) and the fifth processing signal to obtain a sixth processing signal, and the first processing signal d (n) and the sixth processing signal are used as a new output signal of the first processing a (n).
The layout of a three-dimensional space active noise reduction structure is designed according to a typical structure of a feedforward active noise reduction system and is shown in figure 3, the active noise reduction process is shown in figure 4, and the implementation of active noise reduction comprises four links: CCS software platform, DSP hardware platform, experiment platform construction, active noise reduction algorithm. The CCS software platform comprises an anti-phase program and a sine wave cancellation program, wherein the anti-phase program is mainly used for identifying the characteristic frequency of noise and outputting a value opposite to a sampling value or delaying to output a value opposite to the sampling value; the sine wave cancellation program can be decomposed into a combination of a plurality of sine signals based on all signals, the noise characteristic frequency is identified by sampling the reference signal, and then a sine wave signal in the direction of the noise characteristic frequency is output through the anti-phase program. The DSP hardware platform comprises an active noise reduction chip TPA3110D2, an active noise reduction special microphone, a loudspeaker and a DSP28335 development board. The experimental platform comprises an oscilloscope, a hardware platform, a software platform display and a host, and the position of a core device is shown in figure 3.
The active noise reduction algorithm includes a constant step factor algorithm, a Least Mean Square (LMS) algorithm, and a filtering-x LMS (FxLMS) algorithm.
Fig. 5 shows an active noise reduction process. As shown in fig. 5, in the three-dimensional active noise reduction process of the range hood, firstly, software and hardware platforms, such as a CCS software platform, a DSP hardware platform, and the like, are used.
The block diagram of the FxLMS algorithm is shown in fig. 5, and the algorithm comprises a constant step factor algorithm and a least mean square LMS algorithm. Wherein X (n) is an error signal, X' (n) is an estimated error signal, A (n) is a weight coefficient of a primary channel, D (n) is a calculated error signal, B (n) is an input filter weight coefficient, C (n) is a secondary channel off-line identification parameter weight variable, F (n) is a secondary channel off-line identification parameter weight variable estimated value, Y (n) is an input signal, and E (n) is an input signal. Where B (n +1) ═ B (n) -2 μ e (n) X' (n), and μ is a normal number.
The three-dimensional space active noise reduction process of the range hood: and in the initial active noise reduction experiment, the software and hardware platform utilizes CCS programming, hardware equipment and a feedforward experiment platform to realize a sound wave cancellation experiment. The primary and secondary sound sources are located on either side of the experimental platform and the microphones are placed in a central position as shown in figure 3. The hardware platform uses a digital filter, the noise of the range hood is large at first, after the noise reduction platform is installed, a primary sound source sends out a noise signal, a control program sends out an instruction, a secondary sound source sends out another sound wave to offset, and the average reduction is 10db after the hardware platform is used.
In the initial active noise reduction experiment, a CCS programming and hardware equipment, a feedforward experiment platform (such as a feedforward active noise control system) are used to implement a sound wave cancellation experiment, such as a sine wave cancellation experiment in the previous period: firstly, a software platform writes a program to enable a feedforward experiment platform to send out a sine sound wave signal and send out a reverse sine sound wave to offset.
The noise of the range hood is large initially, after the noise reduction platform is installed, a primary sound source 1 (such as collected noise of the range hood) sends out a noise signal, a control program sends out an instruction, a secondary sound source 2 (opposite noise generated by a system through an algorithm) sends out another sound wave to offset, and the average reduction is 10db after the system is used.
In connection with the example shown in fig. 2, a feed forward active noise control system, also called open loop noise control system, requires acoustic information of the range hood, called reference signal. The reference signal is sent to a feed-forward controller, after being processed by the controller, a corresponding control signal is generated, the loudspeaker is driven to output the sound signal to generate a secondary sound field, and then the secondary sound field is superposed with an original sound wave signal transmitted in a physical way, an error microphone detects an error signal formed by superposition of the primary sound field and the secondary sound field and sends the error signal to the controller, and the controller adjusts the intensity of the secondary sound source signal according to a specific algorithm.
In the feedforward active noise reduction structure shown in fig. 2, a noise signal is fed back to the controller through the reference microphone, a residual noise is fed back through the error microphone, and a secondary sound source signal is sent out through the speaker. Its advantage is that the microphone can receive the pure noise of the kitchen ventilator, so the system is an open loop, will not cause any closed loop oscillation and squeal, therefore can debug the circuit independently, make the effect of making an uproar reach the best. The structural design considers the superposition of sound waves and is determined through multiple experiments at multiple points. In the scheme of the invention, a closed type tool is used as an experiment platform in an experiment to simulate a three-dimensional space in a range hood; the hardware equipment of the research experiment platform is added with a new chip, and the hardware module is updated, so that the whole experiment platform is more specialized and precise, and is matched with higher experiment requirements.
In connection with the example shown in fig. 3, the
In connection with the example shown in fig. 4, the FXLMS algorithm is a combination of an FIR filter structure and a Least Mean Square (LMS) algorithm, so that the control system is simple and stable, and is widely used in adaptive vibration noise control, and is also a basic algorithm in the active noise reduction technology. The LMS algorithm is an acoustic wave cancellation algorithm, and the FXLMS algorithm is added with a filter on the basis of the LMS algorithm. In the scheme of the invention, a filtering algorithm, a variable step length algorithm and the like are added, so that more controllable factors are provided for the active noise reduction process.
Since the processes and functions implemented by the electrical apparatus of this embodiment substantially correspond to the embodiments, principles, and examples of the apparatus shown in fig. 1, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.
Through a large number of tests, the technical scheme of the invention is adopted, and the noise reduction platform, namely the active noise reduction device is installed, after the collected noise of the range hood, the secondary sound source is controlled to generate opposite noise according to the noise of the range hood and send out sound waves of the opposite noise to offset the sound waves of the noise of the range hood, so that the active noise reduction treatment of the range hood is realized, and the active noise reduction effect can be ensured.
According to an embodiment of the present invention, there is also provided a noise control method for an electrical device, which corresponds to the electrical device, as shown in fig. 6, which is a schematic flow chart of an embodiment of the method of the present invention. The noise control method of the electrical equipment, namely the active noise reduction method of the electrical equipment, can be applied to the electrical equipment which needs noise reduction treatment, such as a range hood and the like. The noise control method may include: step S110 to step S140.
In step S110, a first noise signal sent by the electrical equipment is collected, and a sound field in which the first noise signal is located is a primary sound field or a primary sound source.
At step S120, generating a second noise signal according to the first noise signal sent by the electrical equipment, where a sound field of the second noise signal is a secondary sound field or a primary sound source; and controlling the primary sound field and the secondary sound field to be superposed so as to realize mutual cancellation of sound wave signals of the primary sound field and the secondary sound field. The arrangement of the propagation direction of the sound wave signal of the secondary sound field and the propagation direction of the sound wave signal of the primary sound field can enable the sound wave signal of the primary sound field and the sound wave signal of the secondary sound field to cancel each other when the primary sound field and the secondary sound field are superposed. For example: the direction of propagation of the acoustic signal of the secondary sound field may be opposite to the direction of propagation of the acoustic signal of the primary sound field.
Optionally, with reference to a flowchart of an embodiment of the method shown in fig. 7, in which the second noise signal is generated according to the first noise signal sent by the electrical equipment, further describing a specific process of generating the second noise signal according to the first noise signal sent by the electrical equipment in step S120, the method may include: step S210 and step S220.
Step S210, generating a noise control signal of the primary sound field according to the first noise signal sent by the electrical equipment.
More optionally, the generating a noise control signal of the primary sound field according to the first noise signal sent by the electrical device in step S210 may include: after a first noise signal emitted by electrical equipment is processed by a feedforward controller, a corresponding control signal is generated, a loudspeaker is driven to output a sound signal corresponding to the control signal to generate a secondary sound field, and then a sound wave signal of the secondary sound field is superposed with an original sound wave signal of a primary sound field; and adjusting the intensity of the secondary sound source signal according to a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm by detecting residual noise formed by superposition of the primary sound field and the secondary sound field. Specifically, the reference signal is collected by a reference microphone and sent to a feed-forward controller, the reference signal is processed by the controller to generate a corresponding control signal, a loudspeaker is driven to output the sound signal to generate a secondary sound field, the secondary sound field is further superposed with an original sound wave signal actually sent through a physical path, an error microphone detects residual noise (error signal) formed by superposition of a primary sound field and the secondary sound field and sends the residual noise (error signal) to the controller, and the controller adjusts the intensity of the secondary sound source signal according to a filtering algorithm, a variable step size algorithm and/or a least mean square algorithm.
For example: the FXLMS algorithm is a basic algorithm for synthesizing and applying an FIR filter structure and a Least Mean Square (LMS) algorithm, so that a control system is simple and stable, and is widely used in self-adaptive vibration noise control and is also used in an active noise reduction technology. The LMS algorithm is an acoustic wave cancellation algorithm, and the FXLMS algorithm is added with a filter on the basis of the LMS algorithm. In the scheme of the invention, a filtering algorithm, a variable step length algorithm and the like are added, so that more controllable factors are provided for the active noise reduction process.
Therefore, the noise control signal of the primary sound field can be better controlled by processing the first noise signal sent by the electrical equipment by using a filtering algorithm, a variable step length algorithm and/or a least mean square algorithm, and the cancellation of the first noise signal by the second noise signal generated based on the noise control signal can be better controlled.
Step S220, generating a second noise signal according to the noise control signal of the primary sound field, and using the sound field in which the second noise signal is located as a secondary sound field or a primary sound source.
For example: an active noise reduction control scheme based on a range hood platform is designed by utilizing three core technical points of a feedforward active noise control system platform built by a DSP, structural design in a three-dimensional space, a self-adaptive algorithm and the like, and the scheme is simple, reliable, good in stability and good in control effect. The noise signal is fed back to the controller through the reference microphone, the residual noise is fed back through the error microphone, and the secondary sound source signal is sent out through the loudspeaker. Its advantage is that the microphone can receive the pure noise of the kitchen ventilator, so the system is an open loop, will not cause any closed loop oscillation and squeal, therefore can debug the circuit independently, make the effect of making an uproar reach the best. The structural design considers the superposition of sound waves and is determined through multiple experiments at multiple points. In the scheme of the invention, a closed type tool is used as an experiment platform in an experiment to simulate a three-dimensional space in a range hood; the hardware equipment of the research experiment platform is added with a new chip, and the hardware module is updated, so that the whole experiment platform is more specialized and precise, and is matched with higher experiment requirements.
Therefore, the control unit and the sound production unit generate a secondary sound field based on the noise emitted by the electrical equipment to perform sound wave cancellation on the primary sound field of the electrical equipment, active noise reduction on the noise of the electrical equipment is realized, and the reliability and adjustability of noise reduction processing can be improved.
Alternatively, the controlling of the primary sound field and the secondary sound field to be superimposed in step S120 may include: the primary sound field is controlled to emit sinusoidal sound signals in a first direction, and the secondary sound field is controlled to emit sinusoidal sound signals in a second direction, wherein the first direction is opposite to the second direction in waveform propagation direction.
For example: in the initial active noise reduction experiment, a CCS programming and hardware equipment, a feedforward experiment platform (such as a feedforward active noise control system) are used to implement a sound wave cancellation experiment, such as a sine wave cancellation experiment in the previous period: firstly, a software platform writes a program to enable a feedforward experiment platform to send out a sine sound wave signal and send out a reverse sine sound wave to offset.
Therefore, by controlling the primary sound field and the secondary sound field to send out sinusoidal sound wave signals in opposite directions, the sound wave mutual cancellation effect is good, and the active noise reduction effect is favorably improved.
At step S130, an error noise signal generated by the superposition of the primary sound field and the secondary sound field is collected.
Adjusting the secondary sound field, such as adjusting the intensity of the secondary sound field, according to the error noise signal generated by the superposition of the primary sound field and the secondary sound field at step S140; and controlling the primary sound field and the adjusted secondary sound field to be superposed so as to realize mutual cancellation of sound wave signals of the primary sound field and the adjusted secondary sound field. Furthermore, the second acquisition unit can continuously acquire error noise signals generated by superposition of the primary sound field and the adjusted secondary sound field, and the first noise emitted by the electrical equipment is subjected to active noise reduction treatment in a circulating mode in sequence, so that the accuracy and reliability of the active noise reduction treatment of the first noise emitted by the electrical equipment can be improved, and the efficiency and effect of the active noise reduction treatment of the electrical equipment can be improved.
For example: by refining an active noise reduction core control system and a basic algorithm, noise cancellation in a stereo field is utilized, and the problem of larger noise caused by sound wave superposition is avoided, so that the noise of electrical equipment such as a range hood in a preset three-dimensional space is obviously reduced. If the electrical equipment is a range hood, the sound information of the range hood is called a reference signal. The reference signal is sent to a feed-forward controller, after being processed by the controller, a corresponding control signal is generated, the loudspeaker is driven to output the sound signal to generate a secondary sound field, and then the secondary sound field is superposed with an original sound wave signal transmitted in a physical way, an error microphone detects an error signal formed by superposition of the primary sound field and the secondary sound field and sends the error signal to the controller, and the controller adjusts the intensity of the secondary sound source signal according to a specific algorithm. The verification proves that the noise of the range hood is relatively high initially, after the noise reduction platform is installed, the primary sound source 1 (such as collected noise of the range hood) sends out a noise signal, the control program sends out an instruction, the secondary sound source 2 (opposite noise generated by the system through an algorithm) sends out another sound wave to offset, and the average reduction is 10db after the system is used.
Therefore, the secondary sound field is generated by utilizing the primary sound field of the noise of the electrical equipment, the primary sound field and the secondary sound field are superposed to cancel the noise in the stereo field, and the noise error generated by superposing the primary sound field and the secondary sound field is utilized to adjust the secondary sound field, so that the phenomenon that the sound waves are superposed to cause larger noise can be avoided, the noise of the electrical equipment such as a range hood in a preset three-dimensional space is obviously reduced, and the active noise reduction effect of the electrical equipment such as the range hood is improved.
In an alternative embodiment, the method may further include: performing first filtering processing on a first noise signal sent by the electrical equipment and acquired by a first acquisition unit; and/or carrying out second filtering processing on an error noise signal generated by superposition of the primary sound field and the secondary sound field acquired by the second acquisition unit.
From this, through setting up the filtering unit, can carry out the filtering to the impurity signal in first noise signal and/or the error noise signal, be favorable to promoting the accurate nature that the control unit handled first noise signal and/or error noise signal.
Since the processes and functions implemented by the method of the present embodiment substantially correspond to the embodiments, principles, and examples of the electrical apparatus, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of the present embodiment.
After a large number of tests verify that the technical scheme of the embodiment is adopted, after the collected noise of the range hood, the secondary sound source is controlled to generate opposite noise according to the noise of the range hood and send out sound waves of the opposite noise to counteract the sound waves of the noise of the range hood, error signals formed by superposition of the noise of the range hood and the opposite noise are further detected, and the signal intensity of the opposite noise is adjusted according to the error signals, so that the noise reduction effect is optimal.
In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.
The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：基于角向超构表面的声涡旋分离器