A Study Of Active Noise Control System Base On One Dimension Harmonic Frequency Of Sound Source

In recent decades, the active noise control (ANC) technology has become a hot research subject in noise control field gradually. With the advantages of light mass, small volume, and excellent Low frequency noise reduction effects, it attracts much attention. The ANC technology in a sealed space has be applied on the noise control of the passenger seat interval in airplane cabin and advanced car engine at present. The noise control platform in the paper makes the ANC technology be applied to opening space and has a good noise reduction effect.Based on the comprehensive analysis of acoustic theory and the theory of adaptive active noise control, the one-dimensional multi-harmonic frequency sound in the pipe is muffled in the experiment. The experiment takes active noise control algorithms based on digital signal processors PAT TMS320F28335.The pipeline pilot noise control system is designed from software and hardware respectively. From the experimental results, pipe silencer effect based on the PAT algorithm is obvious.This paper conducted MATLAB software to simulate. Using sine wave of single-frequency, harmonic frequency, multi-harmonic frequency noise plus Gaussian noise to simulate the noise wave produced by exhauster. Simulation taking the acoustic transmission path transfer function H(z)(refer to secondary acoustic path)of speaker and speaker to the error microphone into account.Carried out off-line estimation of secondary path transfer function. From the simulation result, we can conclude that sine wave of signal frequency plus Gaussian noise processed by the FXLMS algorithm can achieve the effect of noise elimination very quickly. In the simulation of synthesis frequency, the convergence time of error function is longer than single-frequency synthesis noise.The more complex the longer it takes to calculate the noise. The space where exhauster works is more complex than the pipes and other sealed spaces.Cancellation technology is more difficult. But the noise control platform built by DSP can reduce the one-dimensional multi-harmonic sound in real time, so we achieved a good effect on active noise control of the exhauster.