臺灣博碩士論文加值系統

噪音存在於人們環境四周，對人的生理與心理均有其影響，故而對於如何降低或消除噪音，長久以來始終吸引人們進行研究與討論。從已發表的論文顯示，一般之噪音（聲音）控制核心－「演算法」泰半只能針對某特定的噪音做降低或消除，對於複雜的環境噪音則力有未逮，也泰半不適用實際產品（比如助聽器）的發展與運用。
故本研究之主要目的在於討論如何尋求各種方法以消除日常生活中的噪音，這些噪音常發生於特定噪音聲場，例如：通風管路、風扇、公車引擎聲、、、、等。為尋求消除噪音方法，我們將探討噪音消除方法之一：主動噪音控制（active noise control，ANC）之各種演算法。不同於傳統被動式噪音控制（passive noise control，PNC）（如消音器）的消除噪音方法，主動噪音控制是利用人為產生的反噪音，以抵消主要之噪音源，此一方法對低頻週期性噪音之消除尤其有效。本研究將設計建構幾種噪音消除演算法之模型，再以數種預定的模擬噪音條件，模擬、分析、比較其噪音消除的效益，以便將來實際應用時，能夠直接以外在噪音之特徵，快速選取合適之噪音消除的演算法。本論文首先就文獻中各種噪音效除法進行分類，並選擇幾種適用之可適性噪音消除演算法，以模擬方式比較其消除噪音的效果性優劣;噪音消除效果主要是以其收斂時間快慢與訊雜比之提昇度做為評估的依據。實驗是以PC為平台，使用數學軟體MATLAB 6.0內所提供的工具SIMULINK4.0來進行各項演算法的建構與模擬。

Noise exists around the environment. It has effects on humans’ physiological and psychological functions. The noise decay and cancellation has attracted peoples’ researches and investigations for a long time. The literatures have demonstrated that many algorithms have their cancellation effects on special or low frequency noise. However, most algorithms only have limited function for complex noise, and they are then unsuitable for real applications.
The study will investigate different methods and algorithms for the cancellation of different noise, including ventilated duct noise, fan noise, vehicular engine noise…… We focus our effort on the investigation about the algorithms of active noise control. In contrary to passive noise control, active noise control generates an anti-acoustic sound, and superposes sound to the noise for achieve the noise cancellation. It is especially effective for low frequency noise. We will build several algorithm models, and test the model performances by preset noise conditions. The model performances will be simulated, analyzed and compared that will result the basic index for real applications. We first study the different algorithms cited by the literatures, and select the suitable algorithms for model simulation. The simulation will compare the performance of different algorithm through their convergent time and signal-to-noise increases. The simulation will be executed on a personal computer, and the program will be developed using SIMULINK 4.0 of MATLAB 6.0.

目錄
第一章 緒論 …………………………………… 1
1.1 研究動機………………………………………… 1
1.2 研究背景 ……………………………………… 1
1.2.1 何謂聲音 ………………………………… 1
1.2.2 何謂噪音 ………………………………… 2
1.2.3 噪音對人體的影響 ……………………… 5
1.2.4 噪音對聽力的影響 ……………………… 5
1.2.5 噪音控制 ………………………………… 6
1.3 論文內容結構 ………………………………… 8
第二章 文獻回顧……………………………… 9
2.1 前人研究 ……………………………………… 9
2.1.1 噪音消除的應用方面 …………………… 9
2.1.2 噪音消除的方法 ………………………… 10
2.2 ANC效益探討 ………………………………… 12
第三章 研究原理與方法………………… 15
3.1主動噪音控制系統架構 ……………………… 15
3.2 ANC控制器 …………………………………… 17
3.2.1 NLMS 演算法 ………………………………19
3.2.2 Leaky LMS演算法 ………………………… 21
3.2.3 Filtered-X LMS演算法 ………………… 21
3.2.4 Leaky FXLMS演算法……………………… 23
3.2.5 RLS演算法………………………………… 24
3.2.6 FRLS演算法……………………………… 25
3.2.7 MDF 演算法………………………………… 27
3.2.8 FULMS演算法 …………………………… 28
3.3 研究方法 ……………………………………… 30
第四章 實驗建置與研究結果……………… 32
4.1 實驗一 ………………………………………… 34
4.2 實驗二 ………………………………………… 43
4.3 實驗三 ………………………………………… 49
4.4 實驗四 ………………………………………… 54
第五章 討論 …………………………………… 60
第六章 結論 …………………………………… 66
參考文獻 ………………………………… 67

1. A.H. Reyes, E. S. Sinencio and F. D. Carrillo, “ Analog implementation of an active noise controller system for portable audio application,” IEEE Trans. On Circuits and Systems — II：Analog and Digital Signal Processing, 48, 2001.
2. A.K. Wang and W. Ren, ”Convergence analysis of the multi-variable filtered-X LMS algorithm with application to active noise control,” IEEE Trans. Signal Processing, 47, pp 1166-1169, 1999.
3. A.K. Wang and W. Ren, ”Convergence analysis of the multi-variable filtered-X LMS algorithm with application to active noise control,”IEEE Trans. Signal Processing, 47, pp 1166-1169, 1999.
4. A.J. Efron and L.C. Han, ”Wide-area adaptive active noise cancellation,” IEEE Trans. on Circuits and Systems-II: Analog And Digital Signal rocessing, 41, pp 405-409, 1994.
5. C.A. Jacobson, C.R. Johnson, J. Duane ,C.M. Cormick and W.A. Sethares, ” Stability of active noise control algorithms,” IEEE Signal Processing Letters, 8, 2001.
6. C.C. Tan and C.I. Hird, ”Active control of the sound field of a constrained Panel by an electromagnetic actuator -- an experimental study,” ELSEVIER Applied Acoustics, 52, pp 31-51, 1997.
7. D.C. Swanson, S.M. Hirsch, K.M.Reichard and J. Tichy, ”Development of a frequency-domain filtered-x intensity ANC algorithm,” ELSEVIER Applied Acoustics, 57, pp 39-49, 1999.
8. D. Duhamel, P. Sergent, C. Hua and D. Cintra, ”Measurement of active control efficiency around noise barriers,” ELSEVIER Applied Acoustics, 55, pp 217-241, 1998.
9. J.C. Carmona and V.M. Alvarado, ”Active noise control of a duct using robust control theory,” IEEE Trans. on Control Systems Technology, 8, pp 930-938, 2000.
10. J.S. Hu, ”Active noise cancellation in ducts using internal model-based control algorithms,” IEEE Trans. Control Systems Technology, 4, 1996.
11. J.S. Hu and J.F. Lin,,”Feedforward active noise controller design in ducts without independent noise source measurements,” IEEE Trans Control Systems Technology, 8, pp 443-455, 2000.
........