FLOW CONTROL METHOD FOR PROPORTIONAL VALVE OF BREATHING MACHINE

摘要

A flow control method for a proportional valve of a breathing machine. The method comprises: step 1) acquiring a minimum flow value a and a maximum flow value b of a proportional valve and corresponding drive voltage values thereof, uniformly dividing an interval [a, b] into N flow segment intervals, acquiring a voltage at the left endpoint of each of the N intervals as a feed-forward voltage by means of linear fitting, taking the feed-forward voltage as an initial voltage to calculate, through a closed-loop control algorithm, a drive voltage corresponding to a flow at the left endpoint of each interval, and then performing linear fitting on flows and drive voltages of the N intervals so as to establish a linear relationship between the flows and the drive voltages of the proportional valve of a breathing machine; step 2) according to a proportional valve flow value required to be output, firstly finding out the flow segment interval where the value is located, and then calculating a drive voltage value corresponding to the flow value according to the fitted linear relationship; and step 3) adjusting the voltage of the proportional valve to the drive voltage value obtained in step 2), and then the flow output by the proportional valve satisfying a requirement.