Near-Optimal Very Low-Thrust Earth-Orbit Transfers and Guidance Schemes
Near-Optimal Very Low-Thrust Earth-Orbit Transfers and Guidance Schemes
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DOI：
10.2514/1.24836
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发表时间：
2007-03
影响因子：
2.6
通讯作者：
Yang Gao
中科院分区：
文献类型：
--
作者：
Yang Gao
开发了一种新颖的直接方法，用于计算近乎最佳的极低推力地球轨道转移，并为推重比为 10 -5 的低推力加速度推进的航天器构建可行的星载制导方案。解决了具有滑行机制的最短时间和最少燃料轨道转移问题。直接方法采用三种类型的控制律——近地点心切向转向、远地点心惯性转向和分段常偏航转向，在每次转移公转内的不同轨道弧上分别同时改变半长轴、偏心率和倾角。开发了一种分析轨道平均技术，通过计算涉及推力、地球 J 2 和阴影效应的每次转移革命的经典轨道元素的分析增量变化，有效地传播长时间、多次旋转的轨迹。将最优轨道转移问题转化为参数优化问题，然后通过非线性规划求解，并且仅对少数与控制律相关的参数进行优化。以开环方式引导航天器的星载制导方案是根据轨迹优化结果获得的最佳参数开发的。最后，提出了地球轨道转移的数值结果和制导方案的性能。
A novel direct approach is developed for computing near-optimal very low-thrust Earth-orbit transfers and constructing feasible onboard guidance schemes for the spacecraft propelled by low-thrust acceleration with thrust-to-weight ratio on the order of 10 -5 . Both minimum-time and minimum-fuel orbital transfers with a mechanism for coasting are solved. The direct approach employs three types of control laws-the perigee-centered tangential steering, apogee-centered inertial steering, and piecewise constant yaw steering, over different orbital arcs within each transfer revolution to simultaneously change semimajor axis, eccentricity, and inclination, respectively. An analytic orbital averaging technique is developed to efficiently propagate the long-duration, many-revolution trajectories by computing analytic incremental changes in classical orbital elements for each transfer revolution involving thrusting, and Earth J 2 and shadow effects. The optimal orbital transfer problems are converted to parameter optimization problems that are in turn solved by nonlinear programming, and only a small number of parameters related to the control laws are optimized. The onboard guidance schemes that guide the spacecraft in an open-loop fashion are developed based on optimal parameters obtained by trajectory optimization results. Finally, numerical results of Earth-orbit transfers and performances of guidance schemes are presented.