Study Of Trajectory Optimization And Guidance Algorithm For Boost-Glide Missile

Because that development of missile defence systems and proposition of global precise strike, conventional ballistic and winged missiles have not achieved engagement ideally. But boost-glide missile is a new missile combined with ballistic and winged missiles, which is difficult to be defended against. This dissertation studies trajectories optimization and design, integrated navigation and onboard glide guidance for intercontinental boost-glide missile, thoroughly. The main contents of this dissertation are as follows:For establishment of complex trajectories optimization models for boost-glide missile, three problems are studied. Considering many actual constraints, the trajectories shape for sharp-nose intercontinental boost-glide missile is analyzed and proposed. The control mode is proposed based on flight condition. The trajectory is divided into four phases by flight states. The dynamics, propulsion, aerodynamics, aerothermodynamics, and penetration models are described. Based on design requirements of actual trajectory, the optimization models of overall trajectory including of boost, glide and dive phases are established, under the constraints of stage separation, transonic phase, control, dynamic pressure, normal overload, heating rate and wall temperature at stagnation point, waypoints, no-fly zones, maneuvers in kill zones of space-based laser weapon and intercept missile.For solving the foregoing multi-constraints multi-phases trajectories optimization problems, a improved direct shooting method is used to convert the optimal control problems to nonlinear programming problems, which are solved through a sequential quadratic programming. Referred to flight characteristic of boost-glide missile, the characteristic points are selected, and the initial guess of controls and parameters in every phase is given. An exact and fast trajectories optimization software, which is suitable to solve many trajectories optimization problems for boost-glide missile, is programmed.Based the foregoing multi-constraints multi-phase trajectories optimization problems and numerical solution methods and software, the maximum range, maximum reachable domain, optimal attack trajectories and optimal overall penetration trajectories are studied by numerical simulation. The proposed boost-glide-skip trajectory is validated, and the relations between trajectory shape and aerothermodynamic constraints are analyzed. The shape and square area of maximum reachable domain under earth rotation are given. The optimal attack trajectory to strike the target in maximum reachable domain is studied, and maneuvering form to exhaust surplus energy is proposed. The trajectories optimization with the constraints of waypoints, no-fly zones, maneuvers in kill zones of space-based laser weapon and intercept missile is implemented, and the maneuvering form and engagement efficiency are validated. By aerothermodynamic analysis, the proposed surface thermal protection materials and the selection methods of aeroheating constraints are verified. According to all the results and conclusions, the proposed multi-constraints multi-phases trajectory optimization methods and numerical solution methods are validated. These methods and conclusions are helpful to solve other similar problems.A SINS-GPS-CNS integrated navigation system and mean are proposed to satisfy long-time and large-maneuvering flight conditions for boost-glide missile. In launch inertial coordinate system, the navigation and errors spread equations of SINS are given. According to the elements of GPS, the integrated model and measurement equations of SINS-GPS integrated navigation system are established. In response to the elements of CNS and astronomy, the measurement equations of SINS-CNS integrated navigation system are established, and a dynamic relay selection method of navigation stars is proposed to satisfy the measuring requirement of star tracker with big view field. Some strategies are proposed to decrease the influence of aero-optic and blackout, and increase the navigation precision. A partial fusion principle of federated Kalman filtering method is proposed to use in SINS-GPS-CNS integrated navigation system. The numerical results show that SINS-GPS-CNS integrated navigation system and partial fusion principles of federated Kalman filtering method can improve the navigation precision of boost-glide missile under long-time and large maneuvering conditions efficiently, the dynamic relay selection method of navigation stars can satisfy requirement of CNS.To solve the guidance problems of glide phase for boost-glide missile, an onboard glide guidance methodology is proposed. The glide trajectory is approximated with quasi-equilibrium glide condition. An onboard generation methodology of longitudinal reference trajectory is given with constraints of heating, normal load, dynamic pressure and terminal condition. By this method, the longitudinal constrained reference trajectory planning problem is converted into a one-parameter search problem to realize the quick trajectory generation. The glide guidance is divided into longitudinal and lateral problems. The longitudinal reference trajectory is tracked using LQR method. Using a improved lateral guidance strategy, the lateral reference trajectory was generated, and the heading error corridor is established. The final methmetical simulation shows that the methodology for onboard generation of longitudinal glide trajectory can quickly build longitudinal reference trajectory adopting to fly, the tracking controller can realize the good following for longitudinal reference trajectory, and the improved lateral guidance strategy can satisfy the precision requirement of terminal conditions. The Monte Carlo simulation further shows the glide guidance studied herein has pretty strong robustness on primary error and aerodynamic coefficients uncertainty.