Research On Trajectory Design And Guidance Approach For Boost-glide Vehicle

Based on augmenting the range and excellent penetration ability, the boost-glidevehicle becomes one of the focuses currently. For the purpose of developingtrajectory optimization and reentry guidance technology of the boost-glide vehicle,this dissertation studies the properties of the whole trajectory, trajectory optimizationmethod, on-board trajectory generation and tracking guidance, trajectory onlineoptimization and predictor-corrector guidance. The main work and results achieved inthis dissertation are summarized as follows:Based on the planar reentry dynamic model, the rudimentary properties of theboost-glide trajectory are studied. The characteristics of the equilibrium glidetrajectory are analyzed. The influences of burnout trajectory parameters on range areanalyzed comparing with ballistic vehicle. Based on two stage rocket-boost launchingmode, booster parameter is evaluated for mission; the trajectory of boost phase isdesigned.A trajectory optimization approach using Gauss Pseudospectral Method (GPM)for boost-glide vehicle is developed. The optimization models for the boost-glidetrajectory are presented and the principle of GPM is described. Then the GPM isapplied to compute the optimal trajectory of Max range of whole trajectory, theattainable region of reentry flight and the optimal trajectory considering the restrictionof “no-fly zone”.A scheme of reentry trajectory on-board generation and tracking guidance forboost-glide vehicle is discussed. The reentry guidance is divided into longitudinalguidance and lateral guidance, the vehicle’s longitudinal motion is controlled bytrajectory on-board generation and tracking guidance, lateral motion is controlled byheading error corridor. The main contributions of this research are:1. A method ofheight vs velocity(H-V) profile online generation is proposed. The trajectory isdesigned to two segments of cubic curve in reentry corridors, the curve is determinedby terminate range constraint. A nonlinear tracking law is designed using thefeedback linearization method. The reference trajectory is obtained by trajectorytracking, with the range updating method, the H-V profile generation and trackingguidance performed well.2. An improved equilibrium glide trajectory generationmethod is proposed. The equilibrium glide condition is presented and utilized toestablish the approximate relationship between trajectory parameters and convert allpath constraints to the constraints of control variables. The control variables areparameterized, the parameters of control variable and longitudinal reference trajectorycan be solved with terminate range constraint. The corresponding tracking law is designed using linear quadratic regulator theory. Then the3DOF trajectory iscompleted by longitudinal trajectory tracking control and the heading error corridorcontrol in lateral motion. The equilibrium glide trajectory generation and LQRtracking guidance can overcome the disturbances of initial states and aerodynamicsparameters.To improve the performances of conventional numerical predictor-correctorguidance, a pseudospectral-based online trajectory optimization and feedbackguidance algorithm has been developed and evaluated. The feasibility of using onlinetrajectory optimization to predict the trajectory instead of using numerical integrationis discussed. The good performance is obtained by reasonably choose of the controlupdating period and the number of nodes in optimization calculation. This canprovide an approach for apply the numerical predictor-corrector guidance.The guidance laws with terminal angular constraint in dive phase are studied.The research of this dissertation is an innovative application of optimal controltheory on trajectory design and reentry guidance of Boost-Glide vehicle, which willprovide theoretical support for the overall design and key technology development ofthis kind of vehicle.