Research On The Method Of On-line Frequency Extraction For Coriolis Mass Flowmeter

Coriolis mass flowmeter can measure the mass flow rate directly. Due to its highprecision, low requirements for measuring conditions, multi-parameter output, etc, it has beenwidely applied in many industrial fields. Regarding to the signal processing techniques ofCoriolis flowmeter，the analog circuit method were mainly adopted in early days, but thismethod is particularly sensitive to noise, vulnerable to interference, poor in stability andaccuracy. The digital signal processing was applied recently. This subject is a digital signalprocessing approach.A method of On-line frequency extraction for Coriolis Mass flowmeter was studied inthis thesis，and this research will make it possible for the application of coriolis flowmeter inpulsating flow, gas-liquid phase flow and other occasions. The main contents include severalparts as follows:1) The Coriolis flowmeter signal processing model for different flow patterns was putforward based on the understanding of the working principle and signal characteristics of theCoriolis flowmeter..2) The working principle of notch filter and the IIR adaptive notch filter was simulated.3) The adaptive line enhancer was studied based on direct type, lattice and normalizedlattice respectively. Then frequency extraction method of Coriolis flowmeter signal wassimulated.4) Three methods to track the signal model for frequency were studied and theperformance of the tracking accuracy and speed were compared.