17 results about "Active noise control" patented technology

The application relates to the field of active noise reduction technology, in particular to an ANC (active noise control) active noise reduction simulation system, which comprises a first pickup sensor, a second pickup sensor, a simulation module, a microprocessor and a mediation unit. External sound of an ANC earphone is collected by the first pickup sensor, then noise reduction processing is carried out by using a noise reduction controller, internal sound of the ANC earphone is collected by the second pickup sensor, and waveform of the internal sound of the ANC earphone is simulated by the simulation module, then the waveform is compared with a preset optimal waveform by the microprocessor, parameters of a noise reduction filter are adjusted by the mediation unit, and features of the simulated sound waveform are extracted conveniently, the noise reduction module of the noise reduction earphone is systematically and visually adjusted, and noise reduction performance difference between left and right earphones is minimized.

An electronic system with heat dissipation and feed-forward active noise control function includes a fan module, an embedded controller, a reference microphone, a multi-channel speaker module, a beamforming control module and an active noise reduction controller. The beamforming control module controls the orientation of the multi-channel speaker module. The multi-channel speaker module provides anti-phase noise signals to cancel noise according to a speaker control signal. The reference microphone detects broadband noise generated by the fan module in operation to provide a corresponding broadband noise signal. A virtual microphone module of the active noise reduction controller provides a virtual error signal according to a transfer function between the reference microphone and a physical error microphone, a transfer function between the multi-channel speaker module and the physical error microphone and the broadband noise signal, and generates the speaker control signal according to a synchronization signal, the broadband noise signal and the virtual error signal.

The present application belongs to the technical field of active noise control, and particularly relates to a substation active control noise reduction method, device, equipment and medium. The active noise control method provided by the present application divides the noise distribution map of the noise elimination array area into a first grid array by grid division of the active control noise eliminator array corresponding to the noise distribution map. Each first grid is further divided into a second grid array by grid division, and each first grid corresponds to a second grid array. The sound pressure level in each second grid is determined, the sound pressure level of each first grid is determined according to the sound pressure level of each second grid in the second grid array, the control sound pressure level of the corresponding noise elimination unit is determined according to the sound pressure level of the first grid, and noise reduction is further performed. The present application collects the distribution of noise at the discharge interface, each noise elimination unit can independently control the active noise reduction amplitude, and the corresponding noise reduction effect can be adopted according to the noise distribution at the noise discharge interface to accurately adjust the noise discharge in the corresponding area of the noise reduction unit.

This application discloses a noise control method and a near-ear open-back audio device, relating to the field of acoustic processing technology. The noise control method is applied to a near-ear open-back audio device, which includes at least two first microphones. The noise control method includes: acquiring ambient noise signals collected by each first microphone; performing noise pattern recognition based on the ambient noise signals to obtain a target noise pattern; performing noise localization based on the ambient noise signals to obtain a target noise direction; selecting a target noise reduction controller from a plurality of preset noise reduction controllers that corresponds to the target noise pattern and target noise direction; and performing active noise control based on the target noise reduction controller. This application provides a solution for applying active noise control in a near-ear open-back audio device and improving the noise control effect.

The embodiment of the present application relates to the fan technical field, and especially discloses a kind of portable active noise reduction fan, the portable active noise reduction fan includes: shell, shell is a portable shell, with cavity in shell interior, and the air inlet and air outlet that are communicated with each other are respectively arranged at both ends of shell;Fan assembly is set in cavity, for rotating to produce wind pressure, to suck air from air inlet into cavity, and blow out from air outlet;Noise reduction assembly is set in cavity, for real-time acquisition of noise signal inside and outside cavity when fan assembly operates, and according to noise signal to send noise reduction signal;Wherein, noise reduction signal is including air inlet noise, air outlet noise, fan blade noise and / or motor noise dynamic comprehensive noise signal.The present application reduces the noise level when fan operates by the reasonable design of noise reduction assembly function, utilizes noise reduction signal to carry out active noise control to noise signal.

The embodiment of the present application relates to the fan noise reduction technical field, and particularly discloses an active noise reduction method for a portable fan, which comprises: obtaining a noise signal; the noise signal is a dynamic comprehensive noise signal comprising air inlet noise, air outlet noise, fan blade noise and / or motor noise generated when the portable fan is running; noise control processing is carried out on the noise signal based on a pre-trained noise reduction model to obtain a noise control instruction; a noise reduction signal is sent based on the noise control instruction to carry out active noise control on the portable fan; wherein, within a preset error allowable range, the phase of the noise reduction signal and the noise signal is opposite, the frequency and amplitude are the same, and the noise signal is used for destructive interference. The present application dynamically analyzes the dynamic comprehensive noise signal generated inside and outside the cavity when the fan is running, and sends a corresponding noise reduction signal according to the dynamic comprehensive noise signal, so as to realize active noise control on the fan, thereby reducing the noise level when the fan is running.

The application relates to the field of fan noise reduction technology, and particularly discloses an active noise reduction device for a portable fan, which comprises a signal collector arranged in a cavity of the portable fan and used for collecting noise signals generated by the portable fan in real time when the portable fan is running; a signal processor arranged in the cavity and electrically connected with the signal collector, used for calling a pre-trained noise reduction model to perform noise control processing on the noise signals, and obtaining noise control instructions; and a signal generator arranged in the cavity and electrically connected with the signal processor, used for obtaining the noise control instructions and emitting noise reduction signals according to the noise control instructions to perform active noise control on the portable fan; wherein, within a preset error allowable range, the noise reduction signals and the noise signals are opposite in phase, same in frequency and same in amplitude, and are used for performing destructive interference on the noise signals. The application realizes destructive interference on the noise signals by emitting the noise reduction signals, so that the noise level during the running of the fan is reduced.

This invention belongs to the field of industrial noise control technology and discloses an active noise control method for vibration noise in precast beam factories. The method includes the following steps: S1, signal preprocessing and frequency band focusing; S2, secondary path identification and modeling; S3, calculation of the filtered reference signal; S4, initialization of control parameters; S5, calculation of the desired signal for the main path; S6, main loop processing. The beneficial effects of this invention are as follows: 1. An adaptive divergence detection mechanism based on error signal energy monitoring is introduced into the traditional SAS-FxLMS algorithm. When the error energy exceeds a preset multiple of the original energy, the algorithm is determined to be diverging, and a recovery mechanism is automatically triggered. 2. When the norm exceeds a preset threshold, the weight vector is scaled proportionally to reduce its norm to within the threshold range, ensuring the numerical stability of the algorithm. 3. The transfer function models of the main path and secondary paths are optimized according to the characteristics of the target frequency band center frequency (150Hz); the algorithm parameters are dynamically adjusted according to the peak factor, RMS value, and other characteristic parameters of the input signal.

The electronic system includes a fan module, an embedded controller, a reference microphone, a speaker module and an active noise reduction controller. The speaker module provides an anti-phase noise signal to cancel the noise generated by the electronic system in operation according to a speaker control signal. The reference microphone detects the broadband noise generated by the fan module in operation to provide a corresponding broadband noise signal. A virtual microphone module of the active noise reduction controller provides a virtual error signal according to a first transfer function between the reference microphone and a physical microphone at a predetermined fan speed, a second transfer function between the speaker module and the physical microphone when there is no wind pressure and the broadband noise signal, and generates the speaker control signal according to a synchronization signal, the broadband noise signal and the virtual error signal.

This application discloses a method, apparatus, electronic device, medium, and product for active noise control. The method includes: for each channel, determining the coefficients of the corresponding Discrete Fourier Transform (DFT) for that channel, wherein each channel corresponds to a reference signal, a secondary loudspeaker, and an error microphone, and the DFT coefficients are in the form of scalar dot products; determining the filter parameters corresponding to each combination based on the DFT coefficients of each channel; and determining the output signal corresponding to each secondary loudspeaker for controlling the operation of the corresponding secondary loudspeaker based on the filter parameters and the sine and cosine components of each reference signal. The above technical solution uses the coefficients of the DFT in the process of determining the filter parameters, and uses scalar dot products, avoiding vector convolution calculations of the filter, thereby reducing the complexity of NANC and improving noise reduction efficiency.

Disclosed is a method for active noise control (ANC) in an audio playback device. An ambient audio signal and a feedback audio signal are received via a first audio input device positioned outwardly and a second audio input device positioned inwardly on the audio playback device, respectively. An estimated leaked signal is determined based on the ambient and feedback audio signals. An initial anti-noise audio signal corresponding to dominant noise sources within a plurality of sub-bands of the ambient audio signal is extracted. One or more ear canal parameters associated with a user are estimated based on the feedback audio signal, the estimated leaked signal, and the initial anti-noise audio signal. An anti-noise signal is generated for playback via the audio playback device based on the one or more ear canal parameters to achieve the ANC at the audio playback device.

The application discloses an active noise control method and device, equipment and a storage medium. The sound field sound pressure of an external sound field is obtained based on a high-order sensor, the external sound field being a sound field outside a preset circular region of the high-order sensor; a first sound field coefficient of the external sound field is calculated according to the sound field sound pressure, and a target sound field intensity of a secondary sound field is determined based on a first preset relationship between a sound field intensity of the secondary sound field and a second sound field coefficient of the secondary sound field and a second preset relationship between the first sound field coefficient and the second sound field coefficient, the secondary sound field being a sound field within the preset circular region; and finally, the sound power of the secondary sound field is determined according to the target sound field intensity, the sound power being used to control the secondary sound source to generate the secondary sound field so as to offset the external sound field, thereby improving the noise reduction effect.

This application discloses an active noise control method, apparatus, equipment, and medium for grid-connected motors, applied to multi-channel active control systems, and relating to the field of noise control technology. The method includes: acquiring noise data signals and determining the target current filter weight coefficients of a preset active control algorithm based on the configuration information of a preset error sensor and the current iteration step size to obtain the current active control algorithm; determining the target secondary sound source signal and performing theoretical noise reduction derivation and experimental noise reduction experiments based on the target secondary sound source signal to obtain theoretical and experimental noise reduction values; determining whether the noise reduction effect corresponding to the current active control algorithm meets the preset noise reduction requirements for the grid-connected motor; if it does not meet the preset noise reduction requirements, updating the current iteration step size and jumping to the step of determining the current active control algorithm until the preset noise reduction requirements for the grid-connected motor are met. This improves the noise reduction effect of drilling grid-connected machines.

This invention proposes a weighted fusion wind noise reduction method for helmets. The method includes: Step 1: Placing reference microphone 1 inside the helmet, slightly to the right of the chin; reference microphone 2 inside the helmet, at the level of the right ear; reference microphone 3 inside the helmet, at the level of the right temple; and an error microphone at the cochlea of ​​the right ear. The signals picked up by multiple reference microphones are weighted and fused into a single reference signal for feedforward active noise control. Step 2: The reference signal, after being trained by a fixed-coefficient feedforward control filter in Step 1, is superimposed with the feedback reference signal, which is iteratively updated in real time, to jointly act on the active noise control. This invention proposes a physical layout of reference microphones for helmet wind noise reduction and a weighted fusion wind noise reduction method for helmets. It achieves good noise reduction performance with low computational load, low hardware resource requirements, and strong practicality.

The application discloses an active noise control method and device, electronic equipment and a computer readable storage medium, comprising: collecting a noise source signal, modeling the impulse noise component in the noise source signal, and generating a reference signal; based on the error signal collected by an error microphone, inputting the anti-impulse adjustment parameter and the error signal into a preset function to construct an instantaneous cost function represented by the mathematical expectation of the square of the preset function; calculating the gradient of the instantaneous cost function, and deriving an update formula of an adaptive filter weight vector by using a stochastic gradient descent method; at each sampling time, filtering the reference signal by using the weight vector at the current time to generate a controller output control signal, generating a counteracting sound wave through the secondary path, collecting a residual error signal, calculating the weight vector at the next sampling time according to the update formula, and iteratively executing the above operation to complete noise cancellation. The application realizes efficient suppression of the impulse noise.

This wearable electronic device comprises: a speaker disposed in an inner space of a housing forming the exterior thereof; a first microphone which is adjacent to a first opening of the housing, and which is spaced apart from the speaker and receives external sound for active noise control; a second microphone which is adjacent to an output conduit through which a sound output from the speaker of the housing is output, and which acquires sound output from the speaker; and at least one processor which receives analog signals input from the first microphone and the second microphone so as to convert same into digital signals, and which outputs, with respect to the speaker, sound of a second frequency for offsetting sound of a first frequency at the first microphone, wherein an acoustic filter for blocking ultrasonic waves flowing into the first microphone through the first opening can be disposed between the first opening and the first microphone.

This invention discloses an in-vehicle noise reduction system and method for electric vehicles based on active noise control (AVAS). The system includes an AVAS controller, a multi-source signal acquisition module, a dynamic gain adjustment module, an adaptive filtering and processing module, an in-vehicle noise reduction execution module, an external warning compensation module, an error sensing module, and a central control unit. The adaptive filtering and processing module inputs the AVAS reference signal and error signal into a wide-narrow band hybrid ANC algorithm, ultimately generating an anti-phase sound wave control signal with the same amplitude but opposite phase to the original AVAS sound entering the vehicle. The in-vehicle noise reduction execution module causes acoustic interference and mutual cancellation between the played anti-phase sound wave and the original AVAS noise entering the vehicle through the vehicle body path near the passenger's ear canal. This invention not only intelligently and dynamically cancels the AVAS warning noise entering the vehicle, but also maintains or even optimizes the warning sound effect outside the vehicle.