Motion Characteristics Analysis And Trajectory Prediction For Hypersonic Glide Vehicles

Hypersonic glide vehicles attract great attentions from military powers due to advantages such as strong maneuverability and long glide distance.Following the frontiers of development,flight corridor,trajectory characteristics,maneuver characteristics,target tracking and trajectory prediction for hypersonic glide vehicles are studies in the paper.Firstly,flight corridor of hypersonic glide vehicles are analyzed from the perspective of influence factors,existence criterion and Uncertainties,and analytical expressions of motion parameters of equilibrium glide trajectory and skip glide trajectory are deduced,respectively.1)Motion models and equations under simplified conditions are presented,which provides foundations for following studies.2)Models of flight corridor established in D-V profile and H-V profile.Influence factors are discussed and a simple existence criterion is proposed to avoid complex calculation.Uncertainties of flight corridor are also analyzed.3)Trajectory characteristics in Equilibrium glide and skip glide modes are analyzed.Relative functions between speed,height and fight path angle are deduced,and the changing laws of dynamic pressure,total load factor and heating rate with speed are analyzed in equilibrium glide mode.In additional,analytical equations with constant lift-drag-ratios between state parameters are presented followingly.4)Deviations between the initial states and equilibrium glide condition are divided into small perturbations and large deviations.The Qualitative analysis and quantitative analysis are proposed for skip glide trajectories caused by small perturbations,respectively.The numerical simulation method is present for skip glide trajectories under the condition of large deviations.Secondly,maneuver characteristics of hypersonic glide vehicles are analyzed systematically from the perspective of maneuver modes and maneuverability.1)Longitudinal skip maneuver mode,equilibrium glide mode,lateral weaving maneuver mode,lateral turning maneuver mode,space spire maneuver mode and space pendulum maneuver are presented to describe the maneuvers of hypersonic glide vehicles and the controls correspondingly are deduced.2)Flight constraints including heating rate,aerodynamic press,load factor are transferred into the form of angle of attack constraints to validate whether the vehicle has enough maneuverability to realize the designate maneuver.3)Some performance indexes including reachable capacity,lateral maneuver turning capacity and lateral maneuver round capacity to evaluate the maneuverability are detailed.Especially,the reachable capacity is emphasized and the reachable footprints are solved by Gauss Pseudospectral Method.Thirdly,two tracking methods for hypersonic glide vehicles based on aerodynamic parameter estimation and improved current statistic model are proposed,respectively.1)In order to avoid the non-convergence phenomenon of filter caused by overlarge condition number of the covariance matrix of observation errors,error propagation theory is introduced to convert the direct observation into pseudo-observations.2)An approach based on aerodynamic parameters estimation is proposed.The aerodynamic force is modeled as Gauss-Markov process in the term of aerodynamic parameter,which avoids the complex transform of aerodynamic force and simplifies the model with unknown paramjeters.The simulations results indicate that the proposed method has a satisfying tracking precision.3)Perturbations and unknown aerodynamic acceleration are synthetically represented by the current statistical model to establish dynamic models to simplify the tracking model.Due to the limitation of traditional current statistical model algorithm,an improved current statistical model combines adaptive adjustment of covariance and the interacting multiple models of maneuver frequency.Simulation results suggest that the improved method has a better performance that the tradditonal method.Finally,two trajectory predition methods for hypersonic glide vehicles based on typical control law and optimal maneuver model are developed,respectively.1)The trajectory predition method considering the control law is proposed.Assuming that the vehicle has been known,the control variables are modeled and identified,and then the the control variables are predicted after reconfiguration to conduct trajectory predition.2)The trajectory predition method based on optimal maneuver model is proposed,which compares the tracking results of accelerations of an unkown vehicle with the acceletation models established previously and selects the optimal model to predict the trajectory.3)Simulations demonstrate that both the two methods have a high trajectory precision with the absence of the reversal of bank angle.This paper analyzes the motion characteristics deeply and explores the method of tracking and trajectory predition preliminarily.Our research may be taken as a good reference for developing and defensing the hypersonic glide vehicles.