Rapid Generation of Safe Entry Trajectories Based on Safe Flight Corridor Considering Uncertainties

Uncertain factors such as atmospheric density, aerodynamic coefficients, and aircraft mass can have a catastrophic impact on the flight safety of entry vehicles (EVs). It is crucial for EVs to quickly generate safe entry trajectories that consider the impact of uncertainties to execute complex flight tasks such as online target changing. Given this challenge, a rapid generation method of safe entry trajectories is proposed, which is based on the drag-acceleration-profile method employed during space shuttle entry flights. This method can efficiently generate a safe, feasible trajectory while accounting for the influence of uncertain factors. Compared to traditional drag-acceleration-profile methods, the proposed method incorporates the influence of uncertain factors on the boundaries of the flight corridor. It establishes an uncertain flight corridor model, thereby ensuring the safety of the reference flight profile designed within this corridor under actual uncertain flight conditions. Additionally, a simplified design approach for the reference flight profile enables the rapid generation of satisfactory profiles through straightforward parameter iteration or optimization. Simulations demonstrate that this method can efficiently plan gliding flight trajectories that meet safety requirements, exhibiting potential for online trajectory generation and maneuverability assessment.