Dynamic Characteristics Analysis on Symmetric Control of Asymmetric Heavy-Duty Hydraulic Cylinder

Abstract

As an important equipment of electrohydraulic lifting system, heavy-duty cylinder uses asymmetric structure, i.e., non-rod chamber and rod chamber of single-rod piston cylinder. The kind of structure do not ensure equal flow rate between non-rod chamber and rod chamber, leads to different control parameters (including flow gain) on extending and retracting movement of cylinder, and arise asymmetric dynamics. Based on the new definitions of load pressure and load flow, mathematic models of asymmetric hydraulic cylinder on extending and retracting direction are established. Simulation results indicate that the overshoot of extending speed is larger than that of retracting speed, and exists asymmetric features on two moving direction.