Pi controller design for stable solenoid valve system using the scheduling of control gain

Abstract

Solenoid valves are widely used in the industrial field and require systems that include position control. The solenoid valve exhibits a characteristic that the inductance changes depending on the position of the iron core in the solenoid coil, and has a very nonlinear relationship. In the control of the nonlinear system, the control gain of the controller has the inconvenience of adjusting again according to the change of the reference position. In this work, it designed PI controller for position control of solenoid valve system with strong nonlinearity and design gain scheduler in which each gain of controller is automatically calculated as a function of position reference. When designing the gain scheduler, this system first was designed the mechanical part and the electric circuit part separately. And then, all are designed with PI control. The proposed controller has a steady-state error of less than 0.5 [%] and has almost the same control performance with respect to the positional reference input of each step.