Electro-hydraulic Servo System Modeling and Launch Vehicle Engine Structural Vibration Analysis Based on Transfer Path Method

Servo amplifier current dither frequency is 20Hz and peak to peak value is 1mA during a vibration phenomenon at launch vehicle third stage flight test. This paper analyses frequency domain stability of Servo control circuit and servo valve, and builds a physical level simulation model in Matlab/Simscape environment, the simulation results verifies mechanism of dithering phenomenon. According to defects of traditional structural vibration analysis, this research analyses the multi-source load vibration of launch vehicle engine based on transfer pass method, and proves validity of the analysis method through a semi-physical simulation experiment.