利用數位訊號處理器進行管路噪音之主動控制

Active Control for Noises in Ducts using a Dsp-based Electronic Silencer

主動式噪音控制之原理為利用人為方式產生的反噪音去抵消原有之噪音，此一方法在低頻時尤為有效，而控制器之設計乃以數位信號處理器為基礎，並利用最小均方法進行適應控制。人工噪音以及較實際之汽車引擎排氣噪音被用來測試控制效能。實驗結果顯示，比較起被動式噪音控制，主動式噪音控制對低頻噪音確有極佳的表現。文末亦對控制參數之選取準則有所歸納。

Least mean square (LMS) algorithms are employed to actively attenuate the noise fields in ducts. The algorithms are implemented on the basis of a digital signal processor that provides efficient adaptation in a real-time fashion, which is crucial to the control bandwidth associated with the active noise control application. The integrated system has been successfully justified by experimental investigations on synthetic noises in the laboratory as well as the exhaust noise from an automobile engine.