摘要
目前航天器最优转移轨道研究中,常忽略摄动力影响,仅考虑能量最优,且采用常值推力控制量,得到的转移轨道精度低,转移时间长,非理论最优。本文考虑地球非球形摄动力J2的影响,建立时间-能量综合最优性能指标,基于变推力控制量,研究了任意椭圆轨道最优转移问题。建立高斯拉格朗日状态方程,应用Pontryagin极小值原理和共轭梯度法求解最优转移问题;研究了J2摄动力对转移轨道根数、推力加速度和最优转移轨道的影响。结果表明:J2摄动力对转移轨道根数和推力加速度都有影响,不能忽略;时间-能量综合最优转移同时考虑轨道转移时间和能量消耗,优化结果更利于工程应用;最优推力加速度不是常值,即采用常值推力控制量得到的并非理论最优转移轨道。
In the research of optimal Orbital transfer of spacecraft, the perturbations are often ignored and the transfer time and constant thrust are employed. As a result, the optimized transfer orbit isn＇ t the optimal transfer or- bit indeed. Considering these, the paper studied the problem of optimal time-fuel arbitrary elliptical orbital transfer using finite variable thrust （the direction and magnitude both changed）, taking J2 perturbation into account. Chosen the Gauss-Lagrange model as state equations, the time-fuel optimal thrust accelerations and transfer orbits were gained by Pontryagin theory. And the influence of J2 perturbation on orbital elements, thrust accelerations and optimal transfer orbit were studied. The results validated that the J2 perturbation has great impact on the transfer orbit ele- ments and thrust accelerations, making it can ＇ t be ignored. In contrast to minimum-fuel or minimum-time problem, optimal fuel/time transfer orbit credits usefulness in practice. The optimal thrust accelerations are not the constant, proving that the optimal thansfer orbit gained employing constant thrust is theoretically not the optimal orbit.
出处
《计算机仿真》
CSCD
北大核心
2012年第7期130-134,共5页
Computer Simulation
