中央真空集塵器之主動式噪音控制之 實驗設計與測試評估

Experiment and Evaluation of Active Noise Control for Central Vacuum Cleaner

藍凡善(Lang-Van Thang)

中原大學/工學院/機械工程研究所/碩士(2010年)

https://doi.org/10.6840/CYCU.2010.00007

摘要

藉由使用快速計算處理器結合麥克風和有效的控制演算法，主動式噪音控制(ANC)已有許多成功應用的例子，如抽風機、通風設備、洗衣機、自動化設備等等。本研究是嘗試利用主動式噪音控制方法針對中央真空集塵器(CVC)進行減低噪音的可能性。CVC系統產生噪音之數個關鍵噪音源問題，包括如高分貝噪音傳播、在操作時塑膠外殼的震動、在流動和壓力中幫浦吸力快速減弱等。本文主要目標為找出主要噪音來源，並建立實驗設備及結合控制方法，測試評估減噪之效果。經實驗測量與判斷，噪音的主要來源一為來自馬達和風扇轉動，一為來自導管內的管流流動。針對此兩種噪音源，將嘗試設計與測試評估幾種減噪方式。例如，裝置數個控制揚聲器圍繞在馬達和其風扇周圍予以減低噪音、又使用一個控制揚聲器裝設在導管適當位置，分別針對管流流動及兩種噪音源，進行減噪音之測試實驗。假設CVC之噪音源是一致的且未使用DSP處理器支援線上即時之快速計算和控制，本研究是藉由離線方式進行實驗，驗證系統設計方法之功能。由CVC記錄下的真實噪音當作主要噪音源，設計一個簡單的控制方法，即將反向噪音源訊號作為減噪控制訊號，另一控制方法設計為使用X濾波最小均方法 (filter X least mean square)。而控制訊號將傳送第二揚聲器播放以抵消噪音。而且，不同架設控制揚聲器之方式亦將探討其功效。由實驗結果，本文所提出的噪音減低方法可證明有良好的效果，對於CVC系統之噪音減低設計提供一個重要的指標及研究改善方向。

關鍵字

X濾波最小均方法(filter X least mean square) ； 馬達噪音 ； 主動式噪音控制 ； 管流噪音 ； 中央真空集塵器

並列摘要

By means of fast computation device associated with microphone and efficient control algorithm, active noise control (ANC) has been successfully applied to numerous systems such as fans, ventilation system, washing machine, automation, etc. The feasibility of ANC to reduce noise for Central Vacuum Cleaner (CVC) is investigated in this thesis. Several fundamental problems of noise resources in CVC include, for example, high noise radiation, vibration of plastic housing during operation, quick decrease of pump sucking flow and pressure. The goal of this study is to find out the primary noise resources and set up the experiment and evaluate the system performance with a couple of control methods. Through experiment testing and evaluation, the primary noise resources are due to the running of motor and fan as well as the airflow in the duct. To deal with both the noise resources, several approaches are designed and tested for noise reduction. For example, a number of control speakers are implemented around the motor and fan, and a control speaker is implemented on the duct for airflow and for both noise resources. Assuming that the noise resources are consistently generated and no implementation of DSP device for on-line fast computation and control, an off-line experiment is carried out to verify the proposed methodologies. The real noise recorded from central vacuum cleaner uses as primary noise. A simple control method designed by inversing the noise signal and a more comprehensive control method by using the filtered-x least mean squares algorithm are applied to compute control signal radiated by the secondary loudspeaker. Furthermore, various implementations of control speaker are also studied. From the experiment results, the proposed design is verified with good performance of noise reduction. And it gives a significant index and trend of appropriate design of ANC system for noise reduction for central vacuum cleaner.

Keys word: active noise control, central vacuum cleaner, airflow noise, motor noise, filter X least mean square.

並列關鍵字

central vacuum cleaner ； active noise control ； motor noise ； filter X least mean square. ； airflow noise

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