管道复合噪声主动控制系统及其实现

Hybrid Active Noise Control System in Duct and Implementat ion

自适应噪声主动控制(ANC)中,由于FXLMS算法较为简单、计算量较小,使之得到广泛应用。在前馈ANC中,要获得好的降噪效果,参考传感器信号和噪声声源要紧密相关,这在实际复杂系统中较难以满足;反馈ANC系统降噪效果不依赖于声场的相关性,但其降噪频带较窄,而且还存在稳定性问题。复合ANC的方法是将反馈和前馈的方法结合起来,以求取得比单独使用前馈或反馈的方法更好的降噪效果。本文应用基于TI公司的TMS320C30芯片作为控制器的实时的ANC系统,在一风机、通风管路系统上进行ANC试验研究。结果表明应用复合FXLMSANC方法,能获得较理想的降噪效果。

In active noise control(ANC),the FXLMS algorithm has been widely used f or its simplicity and low computational load.In feedforward ANC systems to funct ion efficiently,the primary signal must be highly correlated with the reference signal,However,in complex practical application this condition may not be met;in feedback ANC systems,the cancellation effect does not depend on the noise field coherence,but it is only efficient in narrowband,and may be unstable on some fr equencies.Hybrid ANC combine the feedforward and feedback ANC,it is more efficie nt than either the simple feedforward ANC or adaptive feedback ANC system alone. In this paper a realtime ANC system based TMS320C30 controller is proposed,and several realtime ANC experiments were done on a fanduct system,the results show that hybrid FXLMS ANC can gain more ideal effect.