DFT变换法在科氏质量流量计相位差检测中的应用研究

DFT in the Research of Phase Difference Measurement in Coriolis Mass Flow Meter

提出了一种新的采用DFT(离散付利叶变换)实现科氏质量流量计的相位检测方法.该算法首先从理论上分析存在非整周期采样引起的误差随时间的变化规律,提出通过相位变化修正计算DFT的采样点数,使计算DFT的点数接近整周期,最终获得较好的相位计算结果.仿真试验结果表明,这种方法还能够实现频率跟踪,克服频率变化引起的相位计算误差,提高跟踪精度.

A new algorithm based on DFT is proposed for Coriolis Mass Flow meter （CMF） phase measurment. Primarily , this paper analyzed a diversification caused by nonsynchronism sampling in theory and introduced a technique by means of phase change to modify the calculating sampling point. This method applied for adjusting the sampling point to approach a synchronism and get a precise result of phase calculation. After the simulation, we can conclude that it is a feasible method to track the frequency and eliminates error caused by frequency change, and improves tracking precision.