Dynamic Model and Simulation of Electro-Hydraulic Proportional Valve

In the paper, a modeling of electro-hydraulic servo drive is presented. The authors proposed implementation of a dynamic model of proportional valve with the one of most important non linearity, which is square root flow characteristic. Following model is useful when system has got direct information about position of slider in valve. The Authors proposed to extend that model to electro-mechanic parts with dedicated control cards. An input voltage of real valve was in range +/- 10V and was converted to position of slider by use of transfer function with transport delay and dead zone. The results of simulation and compared data with real object were presented. Similarity of the model and the real data was equal 94% (in the worst case: for a step response with input signal 2V). The best result was achieved for the step response by input signal with 10V (accuracy 99.42%).