Analyzing of influencing factors on dynamic response characteristics of double closed-loop control digital hydraulic cylinder

A digital hydraulic cylinder that uses mechanical closed-loop feedback regulation to realize double closed-loop control of displacement and velocity is designed in this study. Based on the working principle, the transfer function model and AMESim simulation model of digital hydraulic cylinder were established. The influence of pre-opening distance of the four-way reversing valve, ball-screw lead, inner diameter, and load on the displacement error, adjustment time, overshoot was analyzed. The standard regression analysis about the results was carried out as well. The results show the pre-opening distance of the four-way reversing valve has the greatest influence on the dynamic response characteristics of double closed-loop control digital hydraulic cylinder, and three Pearson coefficients are all greater than 0.9. The non-inertial load has a certain influence on the displacement error of the digital hydraulic cylinder. The optimal value of the ball-screw lead and inner diameter which have less effect on the dynamic characteristics of the system are 10mm and 90mm, respectively. Furthermore, the performance tests of the digital hydraulic cylinder sample were carried out.