Experimental research of the operational characteristics and control study of a high-flow proportional valve

Self-regulated control of the flow of oxygen, air, or other gases plays an important role in the design of new high-end medical products. High-flow proportional valves are the main component in determining their overall performance as they influence operating and transient conditions. Therefore, it is important to control the value of the flow through the proportional valve by means of a non-linear model that guarantees precision and above all a control model that allows to deal with the hysteresis effects of solenoid valves. The article presents a methodology for testing a miniature high-flow proportional valve, with a description of the operational characteristics of the elements involved and design of an experimental prototype for the proportional valve control study. The results of the experimental activities are shown, both the conditions of use, operability, and assembly of the components, with special attention to the current controller, Flow Sensor and Analog Digital Converter. For the analysis and identification of the system, MATLAB and Simulink tools are used, which through the use of the ARX and ARMAX approximation methods, the model of the plant to be controlled was identified, making use of the experimental data set of both inputs and outputs of the system in question and two plant models were obtained due to the presence of valve hysteresis. Once the control models were obtained, the implementation of a PI/PID controller was carried out and the validity of the proposal was validated experimentally.