亚轨道飞行器再入可达域快速计算方法

Rapid calculation of entry footprint of suborbital launch vehicles

再入可达域的快速准确计算,对于亚轨道飞行器可行着陆点的选择起着至关重要的作用。针对亚轨道再入可达域问题的特点,通过定义加权的横程、纵程组合性能指标函数,将可达域求解问题转化为组合性能指标最优的控制问题,采用求解精度高、收敛速度快的勒让德伪谱法快速计算得到再入可达域。仿真结果表明,该方法不仅能保持动力学模型精度,所得可达域也能很好地满足再入约束条件。

Rapid generation of accurate reentry footprint is critical for choosing feasible landing sites of suborbital launch vehicles. Reentry footprint problem can be transformed into an optimal control problem based on char- acteristics of the reentry footprint, and the cost function is formulated as a weighted combination of maximum （ or minimum） downrange and crossrange. A direct Legendre pseudospectral method is used to discretize and parameterize the derived optimal control problem directly to a nonlinear programming problem. Numerical simulations have been demonstrated that footprints generated using this method can satisfy various path constraints while retaining the fidelity of the full-state model.