Modeling And Simulation Research Of Fuel Metering Device Based On Rotary Direct Drive Valve

The research of fuel metering device is an important link in the development of engine control system,and its characteristic simulation can help shorten the development cycle,reduce engine design risks,and reduce experimental costs.Rotate Direct Drive Valve(RDDV,Rotate Direct Drive Valve)is directly driven by a motor,which can realize adaptive adjustment of torque according to the status and working conditions of the fuel metering device;because RDDV does not have a small hole structure,it is not sensitive to working fluid pressure,The system has strong anti-pollution ability;at the same time,RDDV cancels sensitive components,magnifying originals and elastic components,and the system structure is simple.With these advantages,RDDV has received more and more attention in the aerospace field,especially in fuel metering devices.However,the structure of the RDDV system that directly drives the spool to rotate through the motor does not have a limit mechanism,which places high requirements on the dynamic response and position accuracy of the system;at the same time,when the finite angle torque motor drives the spool to rotate,it will be subject to unknown disturbances.Therefore,the system is required to have strong anti-interference ability,that is,the robustness,stability and load adaptability of the system must be guaranteed.Therefore,high requirements are put forward for the control system of the fuel metering device.In response to the above problems,this article has carried out the following research:1.The basic working principle of the fuel metering device was studied,and the simulation model of the fuel metering device was established by using AMESim simulation software based on the mathematical model of each component(gear pump,equal-pressure valve,rotary direct drive valve).Perform simulation analysis to verify the correctness of the model;2.Aiming at the problems of slow response of the rotary direct drive valve,large overshoot,and many oscillations,a position loop/current loop dual closed-loop PID control system is proposed,which is combined with fuzzy control to realize the self-tuning of control parameters.Model and simulate the control system on the MATLAB platform.The simulation results show that the above control method can effectively improve the dynamic response of the system;3.By connecting the interface of AMESim software and MATLAB software in series,a joint model of mechanical hydraulic module and control system module is obtained,and the characteristics of the system are simulated and analyzed.First,three groups of different pressure differences were selected to study the steady-state and dynamic characteristics of the equal pressure difference valve;secondly,the opening and output fuel flow characteristics of the rotary direct drive valve under different pressure differences and spool area gradients Perform simulation analysis;finally,from the perspective of system stability,the frequency domain analysis illustrates the necessity of the orifice at the front end of the spring chamber of the equal-pressure valve.At the same time,different orifice apertures are selected to perform time-domain analysis of the system.Explore the influence of the orifice diameter on the system.4.Based on the simulation analysis of the fuel regulation system,the optimal design method of the three parameters of the spring coefficient of the equal pressure difference valve,the cross-sectional area of the equal pressure difference valve and the area of the oil return hole is studied.In this paper,the numerical control fuel metering device based on the rotary direct drive valve is designed,calculated,modeled and simulated,and improved and optimized.It also has a certain engineering value for the development of aero engine control system.