压电式高速开关阀控液压缸位置系统

Aimed at low position resolution and slow response of on-off valve controlled cylinder, a hydraulic cylinder position system controlled by piezoelectric high-speed on-off valve was designed. Firstly, the position system model of on-off valve was built in order to analyze the influence of PWM carrier frequency on the on-off valve flow characteristics. The system structure based on differential flow of double valve is adopted to realize the nonlinear compensation of hydraulic cylinder load flow, which reduced the influence of dead zone on the static and dynamic performance. Then, mechanism and principle of on-off valve controlled hydraulic cylinder position chattering are obtained by analyzing the influence factors of load pulse flow of double valve controlled hydraulic cylinder system, and PWM, PAM and PFM control methods based on the pulse flow are compared.Finally, considering the piezoelectric high-speed on-off valve flow characteristics, a composite control method with PWM and PAM is proposed, which helps the system realize fast and accurate position control by adjusting the duty cycle and flow amplitude according to the error signal and change. Simulation and experimental results show that the positioning accuracy is nearly 1%, which provides a theoretical basis for the application of high-speed on-off valve and control system.