航天飞机三维最优再入轨道及气动加热过程

Three-Dimensional Optimal Reentry Trajectory and Aerodynamic Heating History of the Space Shuttle

本文应用现代控制理论研究了航天飞行器三维最优再入轨道和与轨道参数密切相关的气动加热过程。文中选择飞行器迎角和倾斜角作为控制变量,以飞行器气动加热率和飞行过载沿轨道积分最小作为优化性能指标,按极大原理导出了最优再入轨道有约束控制的非线性两点边值问题。采用了数值优化法——共振梯度法求解了有升力飞行器的最优再入轨道及其热过程。文中以允许误差法讨论了权系数和罚函数的选取方法;对不同速度范围研究了不同的加热模型,按热平衡方程与优化轨道同步迭代的方法求得了算例数值结果。算例的数值结果与文献[9]的数值是一致的。

Zhao in 1984 [1] employed mathematical analysis to study optimal reentry trajectory and time-history of heating rate. Zhao's method is limited to two-dimensional problem and he calculates only heating rate of stagnation point. It still represents the methods that are generally found in the open literature. The authors employ nonlinear programming direct optimization method-conjugate gradient method-to solve the optimization problem of three-dimensional trajectory with constraints. Both the heat balancing eq...