A Coriolis Flowmeter Amplitude Adaptive Control Method Based on Fluid State Detection

Abstract

The invention discloses a Coriolis flowmeter amplitude adaptive control method based on fluid state detection. An ultrasonic transducer is installed at the inlet of the measuring tube of the Coriolis flowmeter. Using the attenuation effect of impurities such as bubbles on the ultrasonic signal, the threshold comparator is used to detect whether the amplitude of the received signal has a sudden change, and to obtain whether the fluid state contains impurities, and then carry out Switching between fixed PID and fuzzy PID amplitude controllers. The method of the invention can not only maintain its high-precision steady-state control performance through the detection of the fluid state, but also improve the dynamic response speed of the system through the self-adaptive switching controller, avoiding the measurement tube from stopping vibration, and quickly rebuilding stable vibration, enhancing scientific The adaptiveness of the amplitude control of the measuring tube of the Coriolis flowmeter improves the reliability and measurement performance of the Coriolis flowmeter under complex working conditions.

Description

technical field [0001] The invention relates to a Coriolis flowmeter control method, in particular to a Coriolis flowmeter amplitude adaptive control method based on fluid state detection. Background technique [0002] The Coriolis flowmeter has the characteristics of high precision, wide range ratio, and good repeatability. It represents the highest level of direct mass flow measurement technology and is widely used in petroleum, chemical, pharmaceutical, food, trade measurement and other industrial fields. Its working principle is to directly measure the mass flow rate by using the Coriolis force which is proportional to the mass flow rate generated when the fluid flows in the vibrating pipeline. [0003] The Coriolis flowmeter works based on the vibration of the measuring tube. It is generally believed in the industry that the amplitude stability of the measuring tube vibration has an important impact on the accurate measurement of the Coriolis flowmeter. It is also foun...

AI Technical Summary

Problems solved by technology

However, when the parameters of the vibration system of the measuring tube are stable, the fuzzy PID control, compared with the fixed PID control, will cause frequent jumps in the PID parameters on the one hand, reduce the steady-state performance of the amplitude control, and have a negative impact on the measurement of the Coriolis flowmeter. , which weakens its high-precision advantages; on the other hand, the fuzzy PID control method needs to calculate and adjust the PID parameters in real time, which requires high data calculation and data storage capabilities of the system, and long-term operation will significantly increase system power consumption and improve Application cost of flow meter

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