Precise flow control method of proportional valve

Abstract

The invention discloses a precise flow control method of a proportional valve. The precise flow control method includes steps of 1, operating the system; 2, initializing; 3, acquiring the flow value of the proportional valve and transforming flow value scales; 4, comparing the flow value with the preset flow allowance range, and executing a step 5 if the flow value exceeds the flow value allowance range; executing the step 3 if the flow value is within the flow value allowance range; 5, preset controlled variable=current control variable+0.8 X controlled quantity full scale X (the preset controlled variable-the current flow value) / the flow full scale, adjusting and outputting the controlled variable and returning to the step 3. Dichotomy and iteration are carried out on the basis of closed loop control, and precise control can be realized.

Description

technical field [0001] The invention relates to a flow control method, in particular to a method for accurately controlling flow by a proportional valve. Background technique [0002] In the current flow control applications, proportional valves are usually used to control the flow, especially in the medical equipment industry, proportional valves are used to achieve precise control of gas flow. The control is performed by directly outputting a control amount to control the opening degree of the proportional valve. realized in open loop. However, in this kind of flow control application, there is a problem of poor performance in practical applications. The reason can be easily analyzed: due to the inherent deficiencies of open-loop control, environmental factors such as: changes in ambient temperature, changes in atmospheric pressure, The influence of these factors exists objectively, and the only difference lies in the magnitude of the influence. To overcome these influen...

AI Technical Summary

Problems solved by technology

However, in this kind of flow control application, there is a problem of poor performance in practical applications. The reason can be easily analyzed: due to the inherent deficiencies of open-loop control, environmental factors such as: changes in ambient temperature, changes in atmospheric pressure, The influence of these factors exists objectively, and the only difference lies in the degree of influence. To overcome these influences, a better environment needs to be constructed to satisfy them, but such a price is high and sometimes even impossible to achieve.

In addition, equipment components will naturally decay with time and environmental factors during application, and the natural decay of components is also the reason for the poor control effect

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