本論文以主動噪音控制系統為基礎，分別提出相位補償與模糊適應控制法則以加強型數位濾波器的性能，並增進主動噪音控制系統的控制能力。首先，本論文將針對噪音控制系統的主體結構以及系統說明，做詳細的介紹。其次，本論文針對目前主動式噪音控制法在控制性能上的限制與瓶頸，分別提出加強型濾波器設計的解決方案；而在控制法則部分，則針對使用數位濾波器設計時常發生的量化及捨入誤差，提出相位補償的概念，此外，針對目前常用的噪音控制法皆需經過相當複雜數學運算的缺點，本論文亦提出一個結合模糊控制理論與適應信號處理的自我調適系統，以簡化控制器的設計並加強系統效能。最後，本論文則分別以實驗驗證與數值模擬的方式，來探討上述所提方法實際應用的可行性。 In this dissertation, the enhanced digital filter designing techniques for the applications of active noise control are proposed. These techniques include two approaches; phase compensated scheme and fuzzy adaptive scheme. One can utilize the proposed schemes on the conventional digital filter designing techniques to enhance the performances of active noise cancellation. The main merit of these approaches is to overcome the nonlinear distortion effect, which arise from the analog devices and quantization, and then help to improve the ability of noise reduction. Secondly, the proposed method can save the computing complexity in realizing an active noise control system. Traditionally, one has to identify the system dynamics of the noise control system including circular duct, speaker, microphone and peripheral electronic device in advance to design a noise controller. This dissertation proposes the fuzzy adaptive algorithm, which can self-tune the free parameters in the active controller during the noise control process. Hence, there is not any plant information that needs to be identified. Besides, the proposed approach can process both the numerical and linguistic information, which helps to design an active noise control system easily. Several experiments and simulations are used to demonstrate the proposed approaches in an acoustic duct. It is proved that using enhanced digital filter techniques, the noise reduction abilities of broadband noises as well as narrowband noises are improved. Besides, the designing procedure of active noise control system is also simplified.
