The Dynamic Performance of an Electrohydraulic Servovalve/Motor System With Transmission Line Effects

Abstract

The transient response of an electrohydraulic servovalve coupled to an axial piston ball motor is analyzed. In particular, the effect of long lines between the servovalve and motor is studied together with coulomb friction effects at the motor. The dynamic characteristics of the basic system with short lines is first established via frequency response measurements coupled with a small signal linearized analysis. Longer lines are then added and the method of characteristics, coupled with a quasi-analytical solution for the motor-end equations, is used to predict the large signal transient response. The importance of coulomb friction damping is established together with damping due to servovalve dynamics.