The Impact of Return Orifices on the Stability of a Four-Way Valve–Controlled Double-Acting Actuator

Abstract

This paper studies the influence of the return and the valve spring rate on the stability of a four-way valve–controlled double-acting actuator. A fully nonlinear model for this system is developed based on the orifice equation. The new model contains both the upstream chamber and downstream chamber for each orifice. The geometry of the return orifice and the valve spring rate has an impact on the stability boundary of the four-way valve–controlled double-acting actuator. A larger return orifice requires using a stronger valve spring to ensure the stability of the system. It is shown that, for the nonlinear system, a stable limit circle can be born from an unstable origin as bifurcation occurs.