Key Control Technology Of Pneumatic Flow Proportional Servo Valve

Pneumatic technology is widely used in today’s society,the work’s process is pollution-free,high efficiency,suitable for most occasions in production and life.As a means of treating respiratory diseases,transnasal high flow oxygen therapy is an application of pneumatic technology in medicine.This technology has strong comfort and can play a key role in respiratory diseases,so it has certain research significance.However,limited by the nature of the gas itself,the stability of the work is affected.In the process of work,the external environment changes,resulting in the output of the gas flow can not maintain a good stability.Therefore,the subject takes transnasal high flow oxygen therapy as the research background,carries on the modeling and simulation to the proportional solenoid valve in the oxygen therapy equipment and researches the control method.Through the study of suitable and efficient control technology,the output gas flow can meet the user’s requirements.The proportional solenoid valve in the transnasal high flow oxygen therapy equipment is the proportional solenoid valve produced by CKD.Mathematical modeling was carried out on the working process of proportional solenoid valve.In the process of modeling,the relevant parameters of proportional solenoid,spring stiffness,length,valve port area,gradient,valve and other structural characteristics were measured,and the working principle of the product was clarified through the product manual.Finally,the mathematical model of the change law of the valve output gas flow with time when the input gas pressure fluctuates is obtained.Then,the simulation of the working process is completed by using Matlab simulink to obtain the change law of the valve outlet flow with time when the gas input signal changes.After that,the proportional solenoid part was simulated based on Maxwell software.By comparing and optimizing the previous magnetic circuit part model,the complete working model was obtained and the control research was carried out based on this.After the theoretical model with engineering application value is obtained,the experimental platform is built.The main components of the experimental platform are STM32F103 RE,proportional solenoid valve,fan,display and so on.After the experimental platform was built,software Keil was used to build the lower computer program,and the upper computer used C# to edit the interface display,graph scaling,parameter setting and other operations.The experimental platform mainly realizes data acquisition based on relevant sensors and open-loop debugging,so as to verify the reliability and accuracy of the mathematical model and modify the parameters of the theoretical model.After that,the simulation model of the valve control system is built in the MATLAB environment and the appropriate control strategy is selected.Through the research,the overshoot suppression caused by the initial signal step and the flow output fluctuation control caused by the air pressure instability were realized,so that the output flow was stabilized at the target value and the response time was improved.The above work provides a theoretical basis and an effective technical way for the development of proportional solenoid valve control system.Based on the results of technical research,the stability control technology of proportional solenoid valve satisfying the established goal is studied.The research of this paper has scientific significance and engineering application value.