Modelling, simulating and dynamic analysis of hydraulic actuators with servosystems

Hydraulic systems are involved almost every phase of industry, including transportation, manufacturing, motion simulators and construction. Hydraulic systems are required in heavy- load applications, whereas pneumatic systems are generally employed in light-load, short stroke, high-speed applications. In industrial applications, fluid power systems are suitable for automation. Especially servovalves and electrohydraulic proportional valves are used for this porpuse. In this thesis, two different electrohydraulic systems are simulated. In the first section, some of the proporties of valves are given in a table and the literature on the modeling, simulation and control of hydraulic systems are reviewed. Then, some basic characteristics of valves and actuators which are the most important part of electrohydraulic systems are studied in the second section. In the third section, mathematical, Simulink® and Bond Graph model of the system components are given. Complete system model is established for simulation in the same section. In the first simulation, a Simulink® model is developed for a servovalve controlled hydraulic motor system. Bond Graph model of the system is developed. Position control is performed by applying PD control to the fourth order system. Relations between system parameters and PD control parameters are investigated, and system behaviours are observed. Simulation of an electrohydraulic elevator system is obtained for different scenarios by the state space equations. The effect of the system parameters are observed on the system behaviour.