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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/65984

    Title: 吵雜環境下之風扇聲音頻譜檢測;Spectrum Detection of the Sound from a Fan within a Noisy Environment
    Authors: 呂家豪;Lu,Chia-hao
    Contributors: 機械工程學系
    Keywords: 風扇檢測
    Date: 2014-08-13
    Issue Date: 2014-10-15 17:19:56 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本論文主要目為在一般辦公室環境噪音下,建立一套可判別風扇是否為良品之儀器設備。由某電子公司提供於無響室所測得五種不同型號風扇之相關資料,如:聲音檔、時域訊號、頻域訊號及風扇頻譜圖,觀察各風扇頻譜圖並配合人耳所聽到的聲音與心理感受,建立不同型號風扇異音判別指標,且整合找出風扇通的用判別指標。
    ;The purpose of this research is to establish the measuring equipment, used within an environment with its level similar to an office, which can determine if a fan is in good condition. The company provided the measurement data, in an anechoic chamber, for five different models of fans. Based on the frequency domain data, one can choose several discrimination indices for examining the Fans. The corresponding critical values of the indices can also be determined.
    The goal of designing the equipment is to measure the fan noise in a quiet room and make the decision between fair or foul in a short period. Two microphones were used. One measures the sound from a fan and the other one measures the background noise. The time domain signals then were processed by a LabVIEW program for signal processing. Based on the technique proposed in this research, the processed signal can remove the background noise. Meanwhile, the fan experimental results of the shortened time of measurement would be discussed. All signal processing formulation and the fan discrimination indices were written in a LabVIEW program which shows lights to indicate whether the fans pass the examination. The entire processing time takes about 2-3 seconds plus the measurement time. This equipment can improve the quality of quality control since it distinguishes the sound humans’ ears cannot tell.
    Appears in Collections:[機械工程研究所] 博碩士論文

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