Simulation modeling of the volumetric hydraulic drive

In the design of a variety of the modern agricultural machines, the hydraulic drive with reciprocating motion for lifting, lowering and moving the working bodies has obtained a wide application. One of the important stages in the design of hydraulic drives and transmissions is a simulation. In connection with the laboriousness of carrying out the full-scale experiment and the cumbersome calculation of mathematical models of hydrosystems, as well as the development of the computing machinery, the simulation modeling has obtained a widespread usage. This type of computer simulation allows to investigate complex systems based on the development of multilink factor models with the visualization of a numerical experiment. The article presents the procedure for the simulation modeling of dynamic processes occurring in the volumetric hydraulic drive. The model is developed on the basis of standard libraries of the computing system MATLAB Simulink. The volumetric hydraulic drive is presented in the form of a structural model and consists of interconnected blocks that on the base of differential equations modeling the operation of a pumping station with a mechanical drive, a safety valve, a three-section four-line hydraulic distributor, double-acting power cylinder with special rod, a hydraulic tank. During the calculation of the simulation model takes into account a change of the modulus of elasticity of the fluid depending on the pressure in the hydraulic system, the parameters of the working fluid, the stiff stop when the extreme positions are reached by the rod of the hydraulic cylinder, the friction between the moving parts in the power hydrocylinder. The developed program allows to simulate working processes at the design stage and obtain the necessary data on the dynamic properties of the hydraulic system in all modes of operation, to demonstrate in the form of graphs and oscillograms, to simplify the analysis of transient processes in the hydraulic system, and also to select the rational design parameters of constituent elements of the volumetric hydraulic drive.