Please use this identifier to cite or link to this item: `http://hdl.handle.net/11455/1992`
 標題: 主動噪音控制之聲管系統辨認與控制實作Identification and Control Implementation for an Active Noise Control Acoustic Duct System 作者: 趙世正Chao, Shih-Cheng 關鍵字: acoustic impedance;音響阻抗;identification;Active Noise Control;Digital Signal Processor;辨認;主動噪音控制;數位訊號處理器 出版社: 機械工程學系 摘要: 本文主要是探討一維聲管主動噪音控制中的邊界音響阻抗值K的辨認 以及次音源系統的模式建立,另外一部份則是利用數位訊號處理器,一維聲 管設備以及其他元件來實現主動噪音控制.在系統辨認上,引用Hull等人的 所推導的一維聲管數學模式,將其轉換成有限項且為實數型態的狀態空間 方程式,其中音響阻抗值K為唯一未知參數,利用遺傳演算法將實驗所得聲 管頻率響應與理論聲管模式計算值做比較以搜尋出最接近於實際聲管邊界 的音響阻抗值.此外次音源系統的模式建立,亦是由實驗配合理論的數學模 式來找出次音源的電壓以及質量流率兩者間的動態特性.所辨認出來的聲 管邊界音響阻抗值與次音源系統的動態特性將提供設計控制器時之參考. 本文最後以數位訊號處理器來作為控制器並實現於實際聲管設備中,驗證 其消音效果.In this thesis, identification and control implementation for an active noise control acoustic duct system is studied. A state space model mathematically defined in real space is first developed base on the one dimensional wave motion model. The acoustic impedance of an end boundary is the only unknown parameter in the model that needs th be found. Genetic algorithm is used to identify the acoustic impedance by minimizing the difference between the experiment frequency response and the computed frequency response from the theoretic real state space model. The dynamic behavior of the actuator in the active noise control system is also investigated. From experimental data, we establish the relation between the input voltage and the output mass flow rate of the actuator. The above results are further used to design active noise controllers which are implemented by digital signal processor(DSP). Control effect is demonstrated throuth experiments. URI: http://hdl.handle.net/11455/1992 Appears in Collections: 機械工程學系所