Research On System Identification,Control And Reentry Guidance For Hypersonic Glider

Hypersonic Gliding Vehicle(i.e.HGV),which flies in a large flight envelope with high speed,has many characteristics such as fast response and strong maneuvering authority.HGV can attack the long range targets precisely in a short period of time.HGV has a strategic influence on national security.A composite BTT control mode with a moving mass and Reaction Control System(i.e.RCS)can avoid the aerodynamic control surfaces ablation and improve control efficiency.However,since the HGV under composite control belong to variable mass and variable centroid multi-body system which has features of large aerospace maneuvering and fast time varying structure,the dynamic modeling,parameter identification,guidance and control system design which deal with many couplings and uncertainties are the key and challenging research areas.These have important signifiance for HGV theory research and engineering practice.The object of this research is the HGV controlled by one moving mass and RCS.The key point of this dissertation is the dynamic modeling of the complicated system,the identification of aerodynamic and RCS parameters,and the guidance and control system design.The major contents of this paper are consisted of the following parts.The dynamic model of the HGV controlled by one moving mass and RCS is studied.Firstly,according to the specific description of the HGV shape and layout,the dynamic models of RCS and aerodynamic parameters are established.Then,based on the momentum theorem and the moment of momentum theorem,the translational dynamic equations and rotational dynamic equations of the system center of mass,and translational dynamic equations of the moving point mass are established.The kinematics model of HGB relative to the ground reference frame is given.Finally,the inertial coupling and the Dutch coupling characteristics for the new control mode are analyzed in detail based on the established dynamic model.The relationships between the rolling stability boundary and Dutch roll stability boundary and the mass and position of the internal moving mass are given.The system parameter identification of HGV is studied.Firstly,in order to accurately estimate the RCS moment,the identification strategy of RCS jet moment,delay time and setting time is design based on the approximate model of RCS moment.Then,in order to improve the effective information content in input and output data,the longitudinal dynamic characteristics of HGV are analyzed and the motion form of internal moving mass is designed based on multi-sine input method.The estimate results are compared with that suing a typical input form,namely a 2-1-1 multistep in condition of both open loop and closed loop control.The results demonstrate the identification precision and the strong robustness for the control gain.Finally,the longitudinal identifiability of aerodynamic parameters are analyzed based on the sensitivity measure.The attitude control system of HGV is studied.Taking into account the inertial principal axis displacement and inertia moment caused by the movement of internal moving mass,the attitude control system of HGV faces with great difficulties.Firstly,for such a serious nonlinear system with time varying aerodynamic parameters and coupling between the structure and the aerodynamics of the vehicle,the control model is derived due to the system dynamics analysis.The attitude tracking control system design is divided into longitudinal attitude control system design and lateral/directional attitude control system design.The actuator of longitudinal attitude is the internal moving mass,while the actuators of lateral/directional attitude are RCS jets.The longitudinal robust adaptive control system is designed via the dynamic inversion control and L1 adaptive control method.The lateral/directional attitude tracking control system is design by using dynamic inversion and PWPM technology.Taking into account many uncertainty(inertia uncertainties,aerodynamic coefficients uncertainties,and additional inertia moment generated by the motion of the moving mass),the tracking performance and robustness of control system are analyzed by Monta Carlo numerical simulation.The robust reentry guidance problem of HGV is studied.Based on the computationally efficient Model Predictive Static Programming(i.e.MPSP)technique,a robust suboptimal reentry guidance law is designed.The terminal velocity can be predicted analytically with high precision in the process of model prediction.The computation efficiency will be improved by the analytical prediction.The path constraints(the load constraint,thermal load constraint and dynamic pressure constraints)are converted into angle of attack constraints,which has been difficult to realize by using traditional predictive guidance methods.Taking into account the bounds on the angle of attack and the bank angle,and the terminal constraints(the three-dimensional position and velocity vector components at the end of the reentry),the reentry guidance law of HGV is designed based on MPSP.Finally,the simulations demonstrated that the proposed guidance has sufficient robustness for state perturbations as well as parametric uncertainties in the model.