Lateral-profile planning:Three-dimensional-profile-based optimal trajectory generation

The conventional re-entry guidance method considerably limits the maneuverability of hypersonic glide vehicles under pre-given angle-of-attack profiles.To address this issue,based on a previous three-dimensional(3D)profile guidance method,we propose a lateral-profile-first 3D profile optimization design strategy to solve the trajectory generation problem under complex conditions involving multiple constraints.Unlike the traditional method,which prioritizes the design of the longitudinal drag acceleration profiles,our method first converted the re-entry flight constraints into a lateral flight corridor,generated the initial lateral profile via parameterization,and solved the 3D profile using the coupling relationship between the longitudinal and lateral motions.The design of the 3D profile requires simultaneous consideration of waypoints,no-fly zones,and altitude profiles;hence,a new 3D profile optimization design model was constructed,and a customized sequential quadratic programming algorithm was employed to solve it.The advantages of the proposed method were demonstrated based on landing footprint results obtained using the lateral profile-first strategy.Finally,simulation results based on the common aero vehicle-high-performance model verified the feasibility and effectiveness of the strategy.