本文利用離散傅里葉變換(DFT) 方法處理科里奧利質量流量傳感器的信號,計算其頻率和相位差,提出一種容易實現的、精度較高的頻率跟蹤方法,實現整周期采樣,保證數字信號處理的精度。研制基于數字信號處理器(DSP) 的實時信號處理系統,其硬件包括信號采集通道、DSP 芯片、邏輯控制電路、液晶顯示器(LCD) 電路、鍵盤輸入電路、溫度檢測電路和輸出電路,其軟件包括監控程序、中斷服務模塊、初始化模塊、相位差測量模塊、頻率跟蹤模塊、鍵盤監控模塊和顯示模塊等。仿真和實測結果表明,本文所研究的方法和研制的系統是可行的、有效的。
關鍵詞　科里奧利流量計　數字信號處理器　離散傅里葉變換　頻率跟蹤
Abstract 　In this paper ,the DFT is used to process signals f rom the sensors of Coriolis mass flowmeter ,and calculate the f requency and the phase difference. In order to achieve the integral period sampling and ensure the precision of digital signal processing ,a new technique that can be easily realized and t rack the f requency with high precision is pro2 posed. A DSP2based real2time signal processing system is developed. It s hardware includes signal sampling channels , DSP chip ,logic cont rol circuit ,LCD circuit ,keyboard input circuit ,temperature detector and output circuit s. It s soft2 ware includes monitor module ,interrupt service module ,initialization module ,phase difference measuring module ,f re2 quency t racking module ,keyboard monitor module and displaying module. The result s of simulations and experiment s have proved that the technique and system in this paper are feasible and effective.
Key words 　Coriolis mass flowmeter 　DSP 　DFT 　Frequency t racking