Research On Predictive Correction Entry Guidance And Control System For Reusable Launch Vehicle

Reusable launch vehicle(RLV)as a new generation of aerospace transport system,has the focus of research of world power.New requirements are imposed on guidance and control system,due to these features concerning high-speed,long-voyage and strong-maneuvering.Base on this,this paper focuses on the design of guidance and control system.Firstly,the latest RLV model of the HORUS-2B is introduced in detail,and a detailed aerodynamic coefficient model is given.And then a six degree of freedom mathematical model of RLV is established,the influence of the earth rotation is considered in the model.For the design of guidance and control system,the corresponding simplified model is also given.Secondly,the attitude control system of RLV is designed by using Backstepping control algorithm.The robustness of the system was improved by design of nonlinear disturbance observer.And then a simple and effective control moment distribution method is designed for the hybrid control problem of RCS and aerodynamic surface.Thirdly,a predictive-corrector entry guidance method is proposed for high lift-to-drag RLV.The quadratic function model is employed to design the bank angle amplitude profile,which can effectively improve the accuracy of reentry guidance.In order to improve the restraint ability of the guidance method to constraints,the modified quasi-equilibrium glide condition was designed.Aiming at the reduction of quasi-equilibrium glide condition flight feature in the end stage of reentry,a feedback correction method is designed to further improve the overload suppression ability of the guidance method.Finally,In order to ensure that RLV successfully completed the reentry mission,two joint reentry flight control systems were designed.The first scheme adopts the direct combination of the predictive-corrector guidance system and attitude control system.In the second scheme,a three-dimensional reentry trajectory is designed firstly by using the predictive-corrector method,and then the trajectory tracking algorithm is designed to complete the whole trajectory tracking task.The simulation results show the effectiveness of the two schemes.