Nonlinear Modeling and Simulation on Electro-Hydraulic Servo Systems with Stochastic Vibration Control

A nonlinear mathematical model was established on electro-hydraulic servo system with stochastic vibration control in order to reproduce reference acceleration power spectrum density (PSD) of 5~500 Hz frequency range accurately. The state dependent riccati equation(SDRE) technology was introduced to acquire system state feedback of variable gain and expand system bandwidth, considering the influence of pressure flow characteristic and servo valve control dead zone. Meanwhile the PSD equalization method was applied to modify the input signal in the frequency domain. According to the analysis in Simulink, the steady fluctuation range of PSD is within±1 dB.