Coriolis mass flowmeter signal processing method based on frequency mixing algorithm

Abstract

The invention discloses a Coriolis mass flowmeter signal processing method based on a frequency mixing algorithm. After adjustment and analog-digital conversion are carried out Coriolis mass flowmeter signals, sampled data are processed in a unitization mode and are mapped to the range from 0 to 1, then frequency mixing calculation is carried out, low-frequency interference, ultraharmonics and noise in the signals are filtered away, the phase difference of two paths of signals is solved, vibration frenqeuncy is caught at the same time, signal frequency and the information of the phase difference of a Coriolis mass flowmeter are obtained, and therefore the mass flow rate and density of fluid medium flowing through a vibration tube are solved. By means of the Coriolis mass flowmeter signal processing method based on the frequency mixing algorithm, the ultraharmonics and noise in the signals are eliminated, the calculation accuracy is high, calculation speed is high, and the frequency range of applicable sensors is wider. The Coriolis mass flowmeter signal processing method based on the frequency mixing algorithm is not only applicable to an ordinary tube type sensor, but also a slightly bent type sensor.

Description

technical field [0001] The invention relates to a digital signal processing method for a Coriolis mass flowmeter, in particular to a signal processing method for a Coriolis mass flowmeter that calculates phase difference information reflecting fluid mass flow based on a frequency mixing algorithm. Background technique [0002] The Coriolis mass flowmeter uses the principle of Coriolis to directly measure the mass flow rate and density of the fluid flowing through the sensor measuring tube. According to the Coriolis principle, when the fluid flows through the sensor measuring tube vibrating at a certain frequency, there is a phase difference between the sinusoidal voltage signal at the outlet and the inlet, and the phase difference is proportional to the mass flow rate of the flowing fluid. In order to improve the measurement accuracy of the Coriolis mass flowmeter, the key lies in improving the measurement accuracy of its vibration frequency and phase difference. [0003] P...

AI Technical Summary

Problems solved by technology

The above methods all require the system to store a large amount of sampling data for filtering and calculation, and the program operation time is long. With the development of sensor miniaturization, the vibration frequency of the measuring tube is increased to more than 300Hz. When the DSP uses the above algorithm, it will not be able to quickly track to two The phase difference of the signal

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