A Research Onhigh Pressure Full-automaticgas Supply Technology Based On Typical Gas Path

In order to improve the efficiency and safety of the gas supply system in space launch,the need of unmanned operation and automatic gas supply is proposed.A full-automatic gas supply system can supply gas according to the orders,reducing about 70% human operation,and monitor system state as well as diagnosis faults,reducing works on system management and fault diagnosis.Based on the demand of unmanned operation,theoretical research,simulation and experiment on schematic design are carried out.The demand on automation,reliability and safety is analysed in this paper.A general gas path schematic and control strategy which can meet most working items are designed based on the typical gas path used at the present.In terms of dynamic gas supply,a formula on pressure difference between static and dynamic situation is deduced,based on which a pressure compensation link is added to the control strategy to anticipate and adjust the static pressure.The artificial neural work is introduced to the space launch gas supply system for the first time.What's more,most research of fault diagnosis strategy are focus on training algorithm instead of data preprocessing and adapting activation function to the system feature.This paper proposes a data preprocessing methodand a simplified activation function to adapt to the new feature.As a result,the scale of the network is reduced by about 75%.Afterwards,a joint simulation model inAMESim and Simulink is built according to the system schemes,control strategies and fault diagnosis schemes.The temperature is calculated according to the first law of thermodynamics and the heat conduction differential equation.The simulations result shows the system can charge the cylinder as it's ordered with a steady temperature rising and that the fault diagnosis system can also judge the fault mode immediately,which shows efficiency and accuracy of the schemes.Finally,a platform with control interface is built to conduct experiments including different target pressure curves.The experiment result depicts the system can follow the curves.The difference is less then 10% between simulations and experiment.Several methods of fault injection are proposed to test the diagnosis schemes.The fault diagnosis system can also locate the fault rapidly and precisely.