| The hydraulic control system of the aeronautical metering valve is a system to ensure that the aircraft can provide stable and accurate fuel to the combustion chamber under any working condition,so as to ensure the stable,safe and reliable operation of the aero-engine.With the increasingly high performance requirements of modern aeroengine,higher requirements are put forward for the hydraulic control system of aerometering valve in order to ensure its stable and efficient work.Therefore,it is of great significance and engineering value to study and improve the structure of the hydraulic control system of the aviation metering valve and to control the fuel flow accurately.In this paper,a fuel regulator in a certain military aero-engine is taken as the research object.The main work contents are as follows:Firstly,using AMESim based metering valve,valve and electro-hydraulic servo valve instruction model,the simulation analysis of the model system,the simulation results show that both instruction valve spool valve die cavity pressure fluctuations,or metering valve spring stiffness changes and the amount of precompression makes instructions jitter of the valve happen,which corresponds with the actual engineering phenomena.Secondly,the dynamical mathematical models of the command valves and metering valves in the system were established by using the mechanism modeling method,and the control oil equation was established by considering the cavity effect.Then,the controllability and stability of the hydraulic control system of the aviation metering valve are analyzed.MATLAB /Simulink tool software is used to establish the simulation model of the control system,and the state changes of the simulation system are simulated.At the same time,the uncertainty of unmodeled system,the uncertainty of pressure distribution in flow field and the uncertainty of model parameters are simulated and analyzed respectively.The simulation results show that the position of the command valve changes with the position of the metering valve,which is not consistent with the actual demand.It is also shown that the uncertainty disturbance of the system affects the accuracy of position tracking.By using AMESim hydraulic simulation software and Matlab/Simulink tool software to simulate the failure phenomenon of the system in the test process,find out the cause of the failure,and put forward two systems to improve the design scheme.Finally,according to different conditions of fuel flow control accuracy and rapidity demands,studied the immunity control algorithm and sliding mode control algorithm applied in metering valve subsystem,respectively with proportional integral(PI)algorithm are compared,and the simulation results show that using the immunity control than PI has stronger resistance to interference,the fuel control precision is improved;The sliding mode control has a faster tracking response than PI,which improves the response speed.The research on control methods under different working conditions has great practical engineering significance. |
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