Drive Control of Proportional Valves Based on Active Disturbance Rejection Control

Abstract To address the problems of high motion impact and low precision in aluminum extrusion systems, a proportional valve was modeled and analyzed, and an active disturbance rejection controller (ADRC) was used for control. First, a mathematical model of the proportional solenoid valve was established via an equivalent model, and the effects of electromagnetic, mechanical and fluid force characteristics were analyzed. The relationship between the electromagnetic force and the current was linearized in the solenoid valve model and the hysteresis effect of the current was taken into account. Second, on the basis of the established solenoid valve model, the ADRC was introduced. On the basis of a traditional second-order ADRC, the extended state observer and error feedback module were linearized to reduce the need to tune the ADRC parameter. The control system was simulated in MATLAB/Simulink. The results showed that the control overshoot of the ADRC was not more than 0.1%; the response time reached 80ms, and the control curve was smoother. This method improves the accuracy of the system, reduces the influence on the motion process, and improves the anti-interference ability of the system against ambient noise compared to the traditional proportional-integral (PI) control. The effectiveness of the ADRC controller in large extruders such as aluminum profiles is verified through simulation analysis and experiment.