Guidance Law for Long Range Reentry Trajectory Tracking for Low-lift Vehicle

A trajectory tracking guidance law is designed for long range reentry trajectory tracking for low-lift vehicle when considering the parameter uncertainty in the reentry process such as atmospheric disturbances. The paper firstly designs the reference drag profile using numerical predictor-corrector method. Then the nonlinear drag-tracking control applied to shuttle entry guidance is improved for the entire entry process of low-lift vehicle with some features in the skip and long range reentry such as the large variation of flight path angle, the long time during entry flight. Further based on the match condition in the feedback linearization theory, the localization of drag-tracking control method is analyzed when considering the parameters uncertainty. Finally, based on the features of the skip trajectory, online trajectory planning guidance method is designed to improve the robustness during the reentry. Simulation result demonstrates online trajectory planning guidance method leads to the higher landing precision and better robustness while subject to significant atmospheric variations.