Design Of High-precision Ultrasonic Flowmeter

Ultrasonic flowmeter, it is a method related to the use of ultrasound, by measuring the flow rate of fluid in the pipeline, and then get the flow of the fluid in the pipe instrument through the relevant processing and calculation, it relates to all aspects of our daily lives. In recent years, with the signal processor technology, large-scale application of digital circuits, as well as the development of new ultrasound transducer, ultrasonic flow measurement technology has made great progress, which has the characteristics of high accuracy, low cost, easy to install, and good stability in complicated environment. It is widely used by industrial production in many fields, such as oil and gas exploration, aerospace, medical testing. Flowmeter is an indispensable tool for industrial development, higher precision and more intelligent ultrasonic flowmeter is very necessary for oil exploration and natural gas industry.This paper is mainly based on the theory of ultrasonic transit-time measurement of fluid flow, it is combined with ARM microcontroller embedded platform to design a new type of high-precision ultrasonic flowmeter. The effect of the ultrasonic flowmeter made by this design and the accuracy of the data has been verified by several simulation experiments.First, introducing the background and current development of ultrasonic flow meter domestic and abroad in recent years. Then finally choose the time difference principle as the core method of this design by analyzing the theories of ultrasonic detection and compare their characteristics.And secondly because of the characteristics of ultrasonic attenuation and ambient noise, the received ultrasonic signal is too weak and does not meet expectations. It is needed to add the corresponding signal conditioning module for processing and further analysis.Then design the appropriate signal acquisition module with the AVR microcontroller core, and send the signal acquisition and processing of data to the computer for post-processing through an Ethernet port.Finally, capture the characteristics of ultrasonic signals on the computer, using MATLAB software, combined with Empirical Mode Decomposition, Hilbert-Huang Transform and other signal processing method for a signal post-processing to get more accurate measurement results, and then design the measurement system with LabWindows /CVI software.After the adoption of experimental platform for fluid flow within the pipeline simulation experiments, and analyze the collected data, this new kind of ultrasonic flowmeter can get a more accurate result.