Research And Design In Four-channel Adaptive Active Noise Controller

Noise pollution is one of the three major pollution in the world. With modern industrial, transportation and construction industry development, the subject of noise pollution and noise control more and more attention by the people. Traditional noise control is research the acoustic method of noise control. It works well at high frequency noise control, but it had little effect at low frequency noise control. Active noise control technology just provides a good solution for low frequency noise control.This dissertation which was according as the theory of active noise control, deduced the basic principle of adaptive active noise control, and analyzed the configurations of control system. Then deduced the FXLMS algorithm and setting up a four-channel adaptive active noise control system simulation model to analyze the factors which influence convergence, stability and noise reduction effect. Used DSP and FPGA to design a four-channel adaptive active noise controller, it includes three parts of the external circuit, FPGA and DSP. The main function of external circuit is make signal to A/D conversion, D/A conversion, amplification, filtering, etc. FPGA take responsible for the logic control of entire circuit, and DSP take responsible for adaptive algorithm. Last, build an adaptive active noise control system to experimental by the adaptive active noise controller.The experimental results show that adaptive active noise system has 2dB-8dB noise reduction in a limited frequency and area, and the controller can achieve the design requirements.