基于数字锁相环的科氏质量流量计信号处理方法

The Signal Processing Method of Coriolis Mass Flowmeter Based on A Digital Phase Locked Loop

针对科里奥利质量流量计信号处理中存在的问题 ,即信号频率在小范围内变化和信号易受谐波干扰 ,采用基于数字锁相环的方法处理科氏质量流量计的信息 ,跟踪信号频率的变化 ,计算相位差。对美国专利提出的方法进行了改进 ,做了仿真。仿真结果表明 ,在有谐波干扰的情况下 ,数字锁相环方法可以准确地跟踪信号频率的变化和计算相位差。

According to the problems of the signal processing of Coriolis mass flowmeter, i. e. the signal frequency varies in a small range and the signals are subjected to the harmonics, a digital method based on a phase locked loop is used to process the signals of Coriolis mass flowmeter, tracks the change of signal frequency and calculates the phase difference. The technique proposed by a United States patent has been improved, and made the simulations. The simulation results show that the digital method based on phase locked loop can track the change of signal frequency and calculate the phase difference accurately when there are harmonic disturbances. And the calculation errors have been analyzed also.