Title: 管路之主動式電子消音器
Active Noise Control for Ducts
Authors: 賴建汶
Jienwen Lai
Mingsian Bai
Keywords: 主動噪音控制;多率訊號處理;多相;梳形濾波器;Active noise control;Multirate signal processing;Polyphase;Comb filter
Issue Date: 2000
Abstract: 在本研究中,我們探討與管路主動噪音控制有關的一些重要問題。其內容主要可分為兩個部分:第一個部分探討了電子延遲對於主動式噪音控制系統的影響,以及如何在控制迴路中利用多率訊號處理(multirate signal processing)的方法來使電子延遲最小化。在這個方法中,我們採用多相(polyphase)的方法來進一步提升計算效能。第二個部分我們提出了一個梳形(comb)濾波器,它被使用來取代空間前饋主動式噪音控制架構中的重複性(repetitive)濾波器。在這個架構中,兩種關於最小均方(least-mean-square, LMS)的演算法被使用。此外,我們也研究了通訊系統裡有關回音消除和噪音抑制的問題。在這些研究中,我們使用了離線模型化(off-line modeling)和適應性濾波器的方法。以上所提及的各種控制方法,均將於一數位訊號處理控制卡上加以實現,透過對此管路系統的詳細設計、分析、與實驗,我們將證明這些方法均有控制效果。
In this paper, we discuss some issues for active duct noise control. The research will be divided into two main parts. First, our work presents a problem of electronic delay in active noise control systems and a multirate signal processing approach is utilized to minimize the electronic delay in the control loop. In this approach, the computation efficiency is further enhanced by a polyphase method. The second main part of this paper describes a comb filter is used to replace the repetitive controller in broadband spatially feedforward ANC algorithms. In this algorithm, two types of LMS-based algorithms are used. In addition, we also handle acoustic echo cancellation and noise rejection in communication system using off-line modeling and adaptive filter techniques. The proposed methods are realized on the platform of a TMS320C32 floating point digital signal processor (DSP) equipped with four 16-bit analog IO channels and they are proven to be valid from the detailed design, analysis, and implementation for the experimental duct system.
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