Footprint determination for entry vehicles based on three-dimensional acceleration profile

In this paper, a footprint determination algorithm for entry vehicles based on three-dimensional acceleration profile is proposed, which solves the problem of fast determination of the entry coverage with complex multi-constraints. The aerodynamic adjustment capability is greatly improved since both the angle of attack and bank are regarded as primary variables, and in this way larger entry footprint is achieved. Furthermore, due to the introduction of quasi-equilibrium glide condition (QEGC), the altitude of the entry trajectory changes smoothly without jumping. Firstly, based on the QEGC, a new type of longitudinal acceleration corridor and lateral lift to drag corridor are designed, and the profiles are chose as the interpolation results of the upper and lower boundaries. Secondly, based on PID theory, a three-dimensional profile tracker is designed to realize the corresponding entry trajectories. Finally, the traversal of the interpolation parameters in the corridors is carried out, and the entry footprint satisfying various complex constraints is obtained. The approach is tested using Common Aero Vehicle-H model, and the results demonstrate that the proposed algorithm can determinate the footprint of entry vehicles rapidly while satisfying all the path and terminal constraints.