科氏流量计振动信号参数估计的最小二乘法

Parameters estimation of Coriolis flowmeter vibration signal based on least squares

振动信号参数估计是科氏流量计振动控制和流量解算的基础。针对科氏流量计振动信号特征,基于最小二乘与函数逼近原理,提出一种适用于科氏流量计振动信号的参数估计方法。该方法利用FFT粗估计出信号频率,据此设定频率搜索区间,解最小二乘方程获得信号余弦幅度、正弦幅度和直流偏移,改变频率逐次逼近真值,使得误差平方和最小,最小误差平方和所对应参数即为参数估计值。仿真分析了估计精度和抗噪性能,对罗斯蒙特F200S型科氏流量计实测信号进行了参数分析与估计,结果表明了该方法估计的准确性和实用性。

The parameters estimation of Coriolis flowmeter vibration signal is particularly important for vibration control and flow calculating. Considering the characteristics of Coriolis flowmeter signals, this paper introduces a parameters estimation method applied to Coriolis flowmeter signals. This method is built based on the theories of least squares and function approximation. The FFT is used to roughly compute signal frequency, which is the foundation of frequency search range. It acquires signal amplitude of the cosine, sine amplitude and dc offset by the solution of least squares equation. The right frequency is searched out by making the minimum squared error. Parameters corresponding to the minimum squared error are the wished parameters. The accuracy and anti-noise performance of the proposed method are analyzed in simulation. Prior experiments focus on the analysis and parameters estimation of the Rosemount F200S Coriolis flowmeter signal wave. Accuracy and practicality of the proposed method are testified by the experiment results.