Research On Entry Trajectory Generation For Hypersonic Glide Vehicles Based On Three-Dimensional Profile

Due to the effects of various severe path constraints and strong motion coupling,the traditional method has the risk of unable to reach the target because of the inability to fully release the maneuvering ability,when it solves the problem of large-scale change of the target and the trajectory generation under the condition of strong constrained complex task.In view of such a problem,a new glide trajectory generation method based on three dimensional profile has been proposed in this dissertation,in which the analysis of three-dimensional reentry corridor modeling and maneuver capability,programming of three-dimensional profile for complex flight mission,trajectory optimization technique under the condition of strong constrained complex task and tracking guidance approach based on three-dimensional profile are carried out.First of all,a flight corridor model based on three-dimensional profile is established,and the method of solving the landing footprint for determining and characterizing the maneuvering capability of the hypersonic glide vehicle is discussed.In order to ensure the feasibility of three-dimensional profile planning,a longitudinal,lateral flight corridor model and three-dimensional flight corridor model with typical path constraints such as maximum dynamic pressure,overload and heat flux in the stagnation point are established,and the characteristics of key parameters in corridor model are analyzed.Based on the three-dimensional flight corridor model,a lateral-first calculation method for landing footprint with three-dimensional profile is proposed.Furthermore,by analyzing the modeling and characteristics of typical ontology and environmental uncertainties during flight,a fast estimation method for solving the influence of uncertainty factors on landing footprint is presented.On next step,a three-dimensional profile planning method based on layered strategy is proposed to solve the problem of gliding trajectory generation under complex flight mission.Firstly,in order to obtain the gliding trajectory which satisfies the requirement of flight task,the theoretical foundation of the three-dimensional trajectory planning is established,in which the mathematical model of the glide section trajectory planning,the feasibility of the three-dimensional trajectory planning and the trajectory planning strategy based on three-dimensional profile are expounded in detail.Secondly,a three-dimensional profile planning method based on longitudinal-lateral direction is studied for simple flight mission.A three-dimensional section planning method is proposed to meet the requirement of the lateral maneuvering task in order to consider the complicated flight task with the constraint of the waypoint and no-fly zone.Based on the sub-plane strategy,after planning the lateral profile that meets the constraint of way-point and no-fly zone,then iterate the longitudinal profile to generate the required three-dimensional profile.Finally,a proportional tracker is designed to validate the proposed method.After that,the optimal design method of three-dimensional profile based on sequential quadratic programming(SQP)and the optimization design method of three-dimensional profile trajectory based on Gaussian pseudo-spectrum method are studied for the optimization design of gliding trajectory with strong constraint on complex flight missions.In order to ensure the design of trajectory along the reference height profile,a three-dimensional profile planning approach based on quasi-equilibrium gliding correction condition is proposed,and the corresponding footprint is given.On this basis,the optimization technique of SQP is employed to solve the discrete lateral profile,so that the generated trajectory meets the constraint of designed height profile and requirement of the complex flight tasks.Aiming at the trajectory design problem of simulating large aerodynamic thermal amount within limited range,a normalized motion model of augmented heat absorption is established.And with the help of the theory of three-dimensional profile trajectory planning,a simulation trajectory optimization method based on Gaussian pseudo-spectral method is explored.At last,a tracking guidance based on updating the three-dimensional profile onboard is proposed to solve the problem of trajectory tracking when considering disturbance.Firstly,in order to focus on the research of on-line updating strategy of three-dimensional profile,a parametric initial three-dimensional fast generator is designed for simple mission.Secondly,in order to ensure that the trajectory generated satisfies the task requirement,a three-dimensional profile online updating strategy based on cross-range control is proposed,which combines standard profile tracker and standard trajectory tracker to form a three-dimensional tracking guidance method.Finally,the simulation experiment is carried out by using the Common Aero Vehicle(CAV–H)model,and the guidance performance of the two methods is compared and analyzed.This dissertation deeply discusses the necessity and feasibility of glide trajectory generation based on three-dimensional profile,enriching and expanding the idea and method of glide trajectory planning based on three-dimensional profile.The work of this dissertation has theoretical significance and applied value in improving the maneuverability of hypersonic gliding vehicle,especially in promoting the development of the standard profile trajectory planning method that is designed to solve a wide range of lateral maneuvering missions.