The use of digital hydraulic to the position control of hydraulic cylinder

The article presents the method of controlling the position of the hydraulic cylinder using hydraulic valves on/off with an appropriate strategy for digital control. Main elements of the hydraulic system under consideration include a group of electromagnetic hydraulic valves and hydraulic cylinder single acting. The control system was implemented in the environment of the real-time system based on MATLAB/Simulink. The digital control strategy is based on a fast enough on and off switching valves causing corresponding motion of the cylinder to the required position. This article presents the advantages and disadvantages of this type of control about the system with the proportional control system. The accuracy of this kind of control depends on the structure, properties of the valves or their static and dynamic characteristics. The results of analysis of the control system have the possibility of controlling the positioning hydraulic cylinder with a rather high accuracy, which can be used in place of proportional control systems. The use of digital control system allows, under certain conditions to obtain cost savings related to a reduction in energy consumption, to get a much better adaptation to variable control systems. This concept is an interesting alternative for the conventional control system and provides opportunities for application in systems, where conventional control is very expensive e.g. water hydraulics or to the clear systems where the use of hydraulic proportional technique is not necessarily, but depends on the user to the possibility of obtaining good quality control at a relatively low cost.