Method for inhibiting frequency mismatching in narrow band active noise control
An active noise control and frequency technology, applied in speech analysis, instruments, etc., can solve the problems of reduced noise suppression effect, frequency mismatch, and errors, etc., to achieve the effect of fast system convergence and small number of weights
Inactive Publication Date: 2017-05-31
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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[0004] For non-acoustic sensors, due to long-term operation, component aging and other reasons, there is often an error between the measured synchronous frequency and the real frequency of the target noise, that is, a frequency mismatch
The impact of frequency mismatch on the narrowband active noise control system is fatal, and the noise suppression effect will be seriously reduced
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[0052] The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings.
[0053] A method for suppressing frequency mismatch in narrow-band active noise control, such as figure 1 , figure 2 As shown, the specific steps are as follows:
[0054] Step 1: Under the condition of a given initial value of the distortion frequency, the AR model is used to automatically track the target noise frequency, and a cosine-type reference signal and a sine-type reference signal are generated.
[0055] The expression of the cosine type reference signal is as follows:
[0056] x a (0)=a,
[0057] x a (1)=a cos(ω),
[0058] x a (n)=-c(n)x a (n-1)-x a (n-2), n≥2
[0059] where x a (0), x a (1), x a (n-2), x a (n-1), x a (n) are respectively the 0th, 1st, n-2th, n-1th, and nth update values of the cosine-type reference signal;
[0060] The expression of the sinusoidal reference signal is as follows:
[0061] x b (...
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The invention discloses a method for inhibiting frequency mismatching in narrow band active noise control. The method comprises the following steps: processing a distortion frequency by virtue of an AR model, so as to obtain a cosine type reference signal and a sine type reference signal; processing the cosine reference signal and a delay signal thereof by virtue of a first adaptive FLANN (functional link artificial neural network) filter so as to obtain a secondary source signal generated from the cosine type signal, and processing the sine type reference signal and a delay signal thereof by virtue of a second adaptive FLANN filter so as to obtain a secondary source signal generated from the sine type signal; superposing the two parts of secondary source signals so as to obtain a secondary source synthetic signal, and processing the secondary source synthetic signal by virtue of a secondary channel so as to obtain a secondary noise signal; superposing and canceling the secondary noise signal and a target noise signal so as to obtain a residual noise signal; and updating weights of the FLANN filters by virtue of an FXLMS (filtered-x least mean square) algorithm, and updating parameters of the AR model by virtue of an LMS algorithm, so as to achieve adaptive tracking of a target noise frequency and to implement a frequency compensating function. The method provided by the invention is low in quantity of the adopted weights and high in convergence rate.
Description
technical field [0001] The invention belongs to the technical field of active noise control, and in particular relates to a method for suppressing frequency mismatch in narrow-band active noise control. Background technique [0002] Compared with the traditional passive noise control method, which is mainly used to control high-frequency signals, the active noise control (ANC, ActiveNoise Control) technology has better performance at low frequencies, and the controller is small in size, which is suitable for controlling periodic or approximate periodic signals. The low-frequency sinusoidal narrow-band noise signal is an indispensable and beneficial supplement to the traditional passive noise control method. [0003] The target narrowband noise is lower in frequency and is usually produced by rotating equipment or devices with reciprocating motion. In a narrow-band active noise control system, in order to avoid acoustic feedback, a non-acoustic sensor is generally used to me...
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Login to View More IPC IPC(8): G10L21/0216G10L21/0208
CPCG10L21/0208G10L21/0216
Inventor 刘剑章月新邓帅博毛梦菲夏国芳
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS