Abstract: In order to improve the controlling performance of the position and pressure hybrid controlling process widely used in hydraulic controlled equipment, the separate position and pressure control process is researched on the established electro-hydraulic servo testing stand at first. The characteristics of each process, the structure and parameters of the controller are affirmed by analyzing the test results. Further the series and the parallel two kinds of pressure and position transform control principle are researched and improved. A new series and parallel combined pressure and position hybrid control method is put forward, which can transform the position control to pressure control without any crash by only changing the set value of position, so the control processes is simplified. Finally the control performance is proved with simulations and experiments. The results are of theoretical and practical significance to the improvement of the production efficiency and performance of the electro-hydraulic control equipment.

Key words: Hybrid control, Position control, Pressure control, Servo system