Dynamic Modeling And Model Reduction Of Manned Lunar Landing Combination Consider With Nonlinear Connection

In the process of manned lunar landing,combination were happen separation and docking many times,forming a variety of combinations.What's more,when combination is in progress of earth-moon transfer orbit powered flight,more obvious attitude changes,speed changes and orbital transforms will appear,which also have rich dynamics characteristics.This paper has chosen the manned lunar combination which experience earth-moon transfer orbit flight as a research object,built the dynamic modeling of combination,analysis nonlinear connected effect on dynamic response of combination,and studied applicable model reduction techniques for combination.The main content is as follows:Firstly,the finite element model of propulsion aircraft,manned spacecraft and vehicle upper stage is established.Dynamic characteristics of the single spacecraft,spacecraft solar panels and combination are analyzed.In the frequency band of the control system,the mechanical model of the combination of propulsion aircraft,manned spacecraft,vehicle upper stage and the combination of propulsion aircraft,manned spacecraft are simplified according to the dynamic characteristics analysis results.Secondly,the dynamic model of propulsion aircraft and manned spacecraft is established use the Lagrange equation of real-quasi-coordinates.The nonlinear all-variables flight dynamic model of combination is established and simplified when the nonlinear connection between cabin structures is regarded as equivalent to nonlinear force and moment.Then,select the PID controller and the controls parameter of combination is designed.The dynamic response of the combination consider nonlinear connection structure have been obtained use the Simulink simulation and the nonlinear connected effect on dynamic response of combination was analyzed.In the end,the model of combination is reduced by three different model reduction methods.The model reduction method suitable for the combination is determined by compares the dynamic responses of the reduced model and the original model with three different model reduction methods and the nonlinear connected effect on reduction accuracy of combination was analyzed.