Adaptive Attitude Control Of Launch Vehicle Based On ADRC

The structural design of slender body and large thin wall of space launch vehicle and the wide application of lightweight composite materials make the flexibility of rocket body increase,the natural frequency decrease,the coupling of rigid body motion mode and elastic vibration mode become more prominent,which brings great challenges to the design of attitude control system.In order to improve the robustness,reliability and adaptive ability of the control system of space launch vehicle,the dynamic modeling and attitude adaptive control of elastic launch vehicle are studied in this paper.Based on the consideration of various loads,constraints,equivalent rigid body motion and elastic vibration of the launch vehicle,the rigid-elastic coupling complex dynamic model and control model of the space launch vehicle are established based on the hybrid coordinate method.Secondly,based on the active disturbance rejection control(ADRC)technology and the linear ADRC theory,the attitude control method of rigid vehicle is proposed.At the same time,aiming at the influence of elastic vibration,the notch filter is designed,and the attitude control system of elastic launch vehicle based on linear ADRC is constructed.Finally,the effectiveness of the proposed method is verified by simulation.In order to improve the robustness,reliability,control parameter tuning efficiency and adaptive ability of space launch vehicle control system,the attitude adaptive control system of the launch vehicle is proposed based on the dynamic model of elastic launch vehicle,and the linear ADRC and BP neural network are integrated.Firstly,the convergence analysis of linear ADRC is given;Secondly,Lyapunov function is constructed to analyze the stability of the closed-loop control system embedded with BP neural network;Finally,the effectiveness of the proposed BP-ADRC control method is verified by simulation analysis of the proposed attitude adaptive control method.Aiming at the elastic dynamic model of launch vehicle and the nonlinear characteristics of actuator dead zone,an adaptive control method of attitude and actuator based on BP-ADRC is proposed.Under the conditions of initial flight environment,aerodynamic parameters deviation,vehicle moment of inertia deviation,gust interference and rudder dead zone nonlinearity,the pitching channel of elastic launch vehicle is simulated and analyzed.The effectiveness of the attitude adaptive control system of space launch vehicle based on BP-ADRC is verified.