A New Linearized Equation for Modelling a Servovalve in Hydraulic Control Systems

摘要

In the procedure of the hydraulic control system design, a linearized approximate equation described by the first order terms of Taylor's series has been widely used. Such a linearized equation is effective just near the operating point. However, pressure and flowrate in actual hydraulic systems are usually not confined near an operating point. This study suggests a new linearized equation for servovalve modelling as a modified form of the conventional linearized equation. And also, methods to determine effective operating points for the new linearized equation and the conventional linearized equation are proposed. From the evaluations of time responses and frequency responses obtained from simulations for a hydraulic control system, the effectiveness of the new linearized equation and the methods to determine effective operating points is confirmed.