A flow control method for ventilator proportional valve

Abstract

The present invention provides a method for controlling a flow of a proportional valve of a ventilator, comprising: step 1) acquiring a minimum flow value a and a maximum flow value b of the proportional valve, as well as corresponding driving voltage values thereof; evenly dividing an interval of [a, b] into N flow segment intervals, acquiring voltages at left endpoints of the N intervals by linear fitting as feedforward voltages, calculating a driving voltage corresponding to the flow at the left endpoint of each interval by a closed-loop control algorithm with the feedforward voltage as an initial voltage, and then linearly fitting the flows and the driving voltages of the N intervals, thereby establishing a linear relationship between the flow and the driving voltage of the proportional valve of the ventilator; step 2) firstly finding, according to the flow value of the proportional valve that needs to be outputted, the flow segment interval on which the flow value lies, and then calculating the driving voltage value corresponding to the flow value according to the fitted linear relationship; and step 3) adjusting a voltage of the proportional valve to the driving voltage value obtained in step 2), then the flow outputted by the proportional valve meets requirements.

Description

technical field [0001] The invention relates to the field of ventilators, in particular to a flow control method of a ventilator proportional valve. Background technique [0002] The ventilator achieves precise control of the output flow by controlling the proportional valve. However, most of the ideal flow characteristic curves of proportional valves used in ventilators are linear, and the control methods basically adopt linear control methods. However, in practical applications, due to the installation and application environment of the proportional valve and the repeatability and consistency of long-term use, the flow characteristic curve of the proportional valve changes, especially the small flow section shows nonlinear characteristics, which is called small flow. Controls pose a big problem. Contents of the invention [0003] The purpose of the present invention is to overcome the above-mentioned defects in the existing ventilator proportional valve control method,...

AI Technical Summary

Problems solved by technology

However, in practical applications, due to the installation and application environment of the proportional valve and the repeatability and consistency of long-term use, the flow characteristic curve of the proportional valve changes, especially the small flow section shows nonlinear characteristics, which is called small flow. control poses a big problem

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