Instability of Poppet Valve Circuit

This review focuses on instability and self-excited vibrations occurring in poppet valves used in hydraulic systems. First, the causes of the instability are considered and then studies on the local instability based on linear theory are reviewed. Second, some global behaviors of the nonlinear hydraulic systems, i. e., hard self-excitation and chaos, are described, mainly based on the author's studies by numerical simulation.