Reentry Trajectory Planning And Attitude Control For Hypersonic Glide Vehicles

With the new changes in the world political and economic pattern and the continuous breakthrough of science and technology in various engineering fields,,mankind began to explore the more challenging areas of space.As a class of important near space aircraft,the hypersonic glide vehicle(HGV)is a non-powered vehicle that is mounted on a rocket or space-based platform,which is transported by the near-earth orbit and re-enters the atmosphere,and then maintains a long-range high-speed(Ma> 5)gliding flight.Because of the technical and tactical do not depend on the engine power,with large space high-speed gliding and maneuverability and other advantages,it is a good fit with the rapid development of the global vision and the background of the times,and has important strategic significance and value,However,the guidance and control of hypersonic glide vehicle in re-entry process challenges many problems such as multi-control target,multi-control constraint trajectory optimization control problem,guidance and control oriented model problem,and the reentry control problem with strong nonlinearity,strong coupling and strong nonlinearity.In this paper,the re-entry trajectory optimization and attitude control of the hypersonic glide vehicle are taken as the core of the research.The main research contents are divided into four parts according to the order of problem raising,problem analyzing,problem solving and problem solving results.The full 6DOF reentry motion equation of the hypersonic glide vehicle is provided,including the reentry kinematics equation and the reentry dynamics equation,and the aerodynamic shape parameter model and the aerodynamic parameter model of the aircraft are given.The aerodynamic characteristics,static stability and open-loop dynamic characteristics of the HGV system are analyzed based on the attitude dynamics equation.The simulation results show that the HGV reentry movement is a typical representative with fast time varying,strongly coupled and unstable nonlinear characteristics.At the same time,model and characteristic analysis laid the foundation for attitude control.The longitudinal reentry optimization trajectory of the hypersonic glide vehicle with multi-control target and multi-control constraint reentry is designed.Based on the direct method,the reentry angle of attack is discretized and combined with the space shuttle reentry angle of attack scheme,and the nominal reentry angle of attack scheme under the velocity profile is given.By introducing the inverse energy concept,the dimensionless 3DOF reentry equation is transformed into energy-based motion equation,which transforms the optimization problem of unknown terminal time into nonlinear programming(NLP)problem in fixed energy interval.Then,the NLP problem is put into the framework of Multi-objective optimization problem(MOP).Constrained Multi-Objective PSO(CMOPSO)is designed based on particle swarm optimization algorithm by the adaptive penalty technique handling the constraint and constraint individual,and normalized non-domination sorting technique handling the multiple objective function optimization.The simulation results show that the optimal method of multi-objective and multi-objective trajectory optimization is based on the Pareto optimal value.The three-channel homogeneous T-S fuzzy model of hypersonic glide vehicle reentry dynamics has been established.Aiming at the problem of homogeneous fuzzy model on nonzero operating points based on Jacobian linearization method,a homogeneous modeling method is introduced to construct the local T-S fuzzy model.By analyzing the open-loop characteristics of the attitude dynamics,the complexity and the approximation of the model are balanced,and the roll rate and yaw rate which behaves of strong nonlinearity and coupling are used as the front variable.So homogeneous T-S fuzzy sub-model has been established.Based on parallel distributed compensation(PDC),the homogeneous T-S fuzzy nonlinear model of HGV reentry dynamics is obtained.The simulation results show that the HGV homogeneous T-S model and the original model have good approximation accuracy at each characteristic point and their neighbour domain,and provide a model basis for the subsequent T-S fuzzy control.Aiming at the problem of HGV reentry attitude control,the system closed loop controllers are designed by introducing T-S fuzzy control strategy.By selecting the appropriate Lyapunov function,the LMI condition for the system stability is given.Based on the reentry T-S fuzzy model with external disturbance,a state feedback controller is designed.Because the system state is not all measurable in the actual engineering,and the system model is usually uncertain in the reentry process.Therefore,based on the T-S fuzzy model with uncertain and external disturbances,a dynamic output feedback controller with observation matrix is designed The LMI condition of T-S fuzzy dynamic output controller which guarantees the stability of the system is given by the Lyapunov stability theory.The simulation results show that the designed T-S fuzzy controller can guarantee the stability of the system with external disturbance and model uncertainty.