Post-filtering-structure active control method of impulsive noise

Abstract

The invention discloses an adaptive filtering method for active control over impulsive noise. According to the adaptive filtering method for active control over the impulsive noise, a weighted sum of the square of the Euclidean norm between a coefficient vector of a current filter and coefficient vectors of all the former filters is defined as an objective function, and the objective function is minimized under the constraint condition that a posterior error is zero. The adaptive filtering method for active control over the impulsive noise comprises the following steps of (1) initializing coefficients w(n) of the adaptive filter; (2) obtaining errors e(n) between output signals and desired signals of the adaptive filter; (3) updating system controller coefficients in sequence, wherein the n is a time serial number, a mu is a step-length factor, and a u(n) is a reference signal obtained after filtering is carried out on a secondary channel model; (4) enabling the updated system controller coefficients to pass through a low-pass filter, namely, a selected rho is larger than zero and smaller than one. According to the adaptive filtering method for active control over the impulsive noise, priori knowledge of the impulsive noise is not needed, estimation of characteristic parameters of the impulsive noise is not needed, the adaptive filtering method for active control over the impulsive noise has good noise abatement capacity and robustness to the impulsive noise, and operation is easy.

Description

1. Technical field [0001] The invention relates to a feedforward active control adaptive filtering method of impulse noise, in particular to a stability improvement method of active noise control. 2. Background technology [0002] In order to cope with the increasingly serious noise pollution, active noise control has been recognized as a technology alongside traditional passive noise control methods. Active control of noise is the technique of actively creating a sound field to cancel out another existing sound field. The basic process is: use a microphone (often referred to as a reference microphone) to extract the information of the existing noise, and generate an anti-acoustic signal (often referred to as a secondary signal) after being processed by the active controller in "real time", and then use a speaker (often referred to as a secondary signal) to called the secondary source) plays the anti-acoustic signal in "real time". The antiacoustic signal destructively int...

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Problems solved by technology

The patent I have been authorized (active control method of impulse noise based on logarithmic transformation) is an improvement for this problem, but its logarithmic operation has higher requirements on the hardware system in practice

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