Study on Dynamic Characteristics of DC Valve in Electro-Hydraulic System Using CFD Simulation

摘要

The development of an intelligence control system has presently been widely studied for application in areas of automation industries, especially an electro-hydraulic system (EHS). Usually, it has the position, force and speed controls which are sensitive to change in the system parameters. Hence, a multi-input multi-output (MIMO) fuzzy controller has recently been proposed to control those parameters in a complex system. However, a mathematical model of the EHS which included the dynamic parameters has not yet been clarified. The objective of this paper is to analyze numerically the dynamic characteristics of the directional control valve (DCV) and also the flow behaviors in the electro-hydraulic system control. The spool displacements of 4/3 hydraulic closed center DCV and flow-pressure coefficient were simulated with the computational fluid dynamics (CFD). Furthermore, this paper presents CFD results, which explain the flow behaviors related with the dynamic characteristics of flow-pressure coefficient. The simulation results show that those coefficients show non-linear correlation with the opening spool displacements.