電腦風扇動平衡測試儀即時數位濾波系統開發

Development of Real-Time Filter System for Computer Fan Balancer

洪家彬(Jia-Bin Hong)

指導教授 ： 劉興華

國立臺北科技大學/機電學院/車輛工程系所/碩士(2005年)

摘要

本研究利用數位訊號處理技術與嵌入式系統，對於現有的風扇動平衡檢測儀設計出即時頻譜分析與數位濾波系統，使動平衡檢測儀量測的電腦風扇振動訊號進行數位訊號之擷取與資料分析，改善現有動平衡檢測儀使用類比濾波器，如功能單一性、類比元件精密度不高與老化現象等缺點。在數位訊號處理技術部份，利用有限時間區段單位脈衝響應(Finite Impulse Response，FIR)濾波器中的窗型函數(Window function)來設計數位濾波系統。硬體部分包含三大項：(1)嵌入式系統：可程式化數位信號處理器(Programmable Digital Signal Processor，PDSP)發展模組；(2)紅外線光纖感測器：做為風扇轉速與不平衡相位判斷；(3)電容式位移感測器：做為風扇不平衡振動量的檢測依據。經由風扇動平衡檢測儀類比電路的輸出訊號進行訊號分析，並利用數位濾波器軟體設計與頻譜分析，做為判斷風扇質量不平衡相位及不平衡量的依據。程式發展初期利用MATLAB軟體開發以減少C程式語言反覆驗證的時間，Signal Processing Toolbox與Filter Design Toolbox被用來設計數位濾波器程式，SIMULINK工具則被用來模擬風扇機構的不平衡振動量，最後並針對數位濾波器參數設計、數位濾波器濾波效能、快速傅立葉反轉換時域效能三項進行深入討論。未來可依照程式設計流程與數位濾波器參數設計專屬之DSP晶片電路與程式碼降低生產成本。亦可做為往後產品製程上的相關資料庫建立與比對。

關鍵字

動平衡 ； 振動 ； 數位信號處理器 ； 數位濾波 ； 嵌入式系統

並列摘要

This research focus on the application of Digital Signal Processing Technology & Embedded System to design a Real-Time Spectrum Analysis & Digital Filter System for the fan balancer. This system can capture digital signal to analyze the vibration signal of computer fan and resolve current drawback of analog filter system, such as simplex-function, resolution not enough on analog component, aging condition, With regard to the Digital Signal Processing Technology, Window Function of Finite Impulse Response (FIR) is used to design digital filter system.
Three hardware portion are needed for realized the DSP based fan balancer (1)Embedded system- which is Programmable Digital Signal Processor (PDSP) Evaluation Module (EVM) (2)Infrared & fiber optical sensor- used to capture fan rotation speed & unbalance phase (3) Capacitance displacement sensor- used for the unbalance offset measurement. Next the measurment and the software simulation result were used to judge the amount of unbalanced mass & phase. On the initial stage to reduce the cumbersome trial of coding via C compiler, the MATLAB software and SIMULINK predict the unbalance vibration amplitude. Finally, the discussion focus on the parametric design of digital filter effecting the performance on digital filter and Inverse Fast Fourier Transform to time domain. In the future, the system can be used to design DSP chip circuit and code in accordance with the program design procedure and parameter design of digital filter to reduce the cost and time. Through this technique and experience will be helpful on the relevant database establishment and comparison for product process.

並列關鍵字

Balancing ； Vibration ； DSP ； Digital Filter ； Embedded System

參考文獻

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