Near-Optimal Control of Altitude and Path Angle During Aerospace Plane Ascent
Near-Optimal Control of Altitude and Path Angle During Aerospace Plane Ascent
复制标题
航空航天飞机上升过程中高度和航迹角的近乎最优控制
DOI：
10.2514/2.4114
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发表时间：
1997
影响因子：
2.6
通讯作者：
K. Mease
中科院分区：
文献类型：
--
作者：
Jean;K. Mease
本文讨论了空天飞机在后跨音速吸气式上升段的高度和航迹角控制，其目标是使燃料消耗最小化，并遵守飞行器的包线。基于能量/质量和高度/路径角动力学之间的时间尺度分离，高度/路径角控制问题在奇异摄动框架中被视为初始边界层问题。通过求解相邻最优问题得到了近似最小燃料初始边界层控制的反馈律.为了便于推导，在边界层中使用适当的惩罚函数来模拟对慢解有效的状态约束.只要边界层中的临时约束违反是可接受的，那么相邻最优反馈律就能很好地执行.一个替代的线性反馈法推导出计算增益，以减少约束违反，但这种法律导致增加燃料的使用。本文给出了空天飞机升力体锥角和马赫数为8时的数值计算结果。结果表明，当允许峰值动压增加时，燃料使用和控制活动减少。所用车型的燃料使用差异很小。
Altitude and e ight-path-angle control during the posttransonic airbreathing segment of aerospace plane ascent is addressed, with objectives to minimize fuel usage and respect the vehicle e ight envelope. Based on a time-scale separation between energy/mass and altitude/path-angle dynamics, the altitude/path-angle control problem is viewedina singularperturbation framework asan initialboundary-layerproblem. Afeedbacklawapproximating theminimum-fuelinitialboundary-layercontrolisobtainedbysolvinganeighboring-optimalproblem.Tofacilitate this derivation, the state constraint that is active on the slow solution is modeled in the boundary layer using an appropriatepenaltyfunction.Theneighboring-optimalfeedbacklawperformswellaslongastemporaryconstraint violations are acceptable in the boundary layer. An alternate linear feedback law is derived with gains calculated to reduce constraint violations, but this law leads to increased fuel usage. Numerical results are presented for a lifting-body cone guration of an aerospace plane and a Mach 8 e ight condition. The results show that fuel usage and control activity are reduced when the peak dynamic pressure is allowed to increase. Differences in fuel usage are small for the vehicle model employed.