Abstract: A new type of digital directional valve is presented. The configuration is developed by the utilization of the two-motions-freedom of a single spool. To solve the contradiction between the response speed and the quantitative accuracy which characterizes the previous valve of the same sort, a specially designed tracking program is adopted to the stepper motor control to smooth angular displacement output. Experimental results show that both static and dynamic performances of the digital valve are superior to these of proportional valves of various types.

Key words: Digital control, Hydraulic, Valve