A nonlinear dynamic model for an unconventional, commercially available electrohydraulic flow control servovalve is presented. The two stage valve differs from the conventional servovalve design in that: it uses a pressure control pilot stage; the boost stage uses two spools, instead of a single spool, to meter flow into and out of the valve separately; and it does not require a feedback wire and ball. Consequently, the valve is significantly less expensive. The proposed model captures the nonlinear and dynamic effects. The model has been coded in Matlab/Simulink and experimentally validated.

Issue Section:
Technical Papers
Keywords:
servomechanisms, electrohydraulic control equipment, flow control, pressure control, nonlinear dynamical systems, nonlinear control systems, digital simulation, control engineering computing
Topics:
Dynamics (Mechanics), Flow (Dynamics), Flow control, Pressure, Pressure control, Valves, Steady state, Design
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Copyright © 2002
 by ASME
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