摄动情况下有限推力轨道转移与交会联合优化

摘要

远程轨道转移与近程交会是空间交会任务的2个重要阶段,前后衔接,但研究模型不同,任务约束要求差异很大,经常只能分别优化设计.研究摄动情况下的有限推力轨道转移与交会联合优化设计问题,建立了精确的有限推力轨道转移和空间交会模型,推力幅值恒定,优化性能指标均为时间最短.采用Gauss伪谱法将2个最优控制问题分别转化为非线性规划(nonlinear programming,NLP)问题,再建立其联系,构建成一个NLP问题,获得整体优化.最后,通过一个仿真算例,验证了有限推力异面轨道转移与空间交会联合优化.求解过程和结果表明,该方法对初值敏感度小、鲁棒性强、收敛快,满足各类约束条件,能为相关的多阶段整体优化问题求解提供参考.%Orbit transfer and rendezvous,which are influenced orderly but modeled,constrained differently,are parts of a rendezvous task in space as two important phases.In general,that optimum is dealt with respectively.The research is done in the study of comprehensive optimization for the two phases of finite thrust with the impact of perturbation.Firstly,the accurate models of orbit transfer and rendezvous are both brought out.In the model,the thrust magnitude is fixed.While the time for orbit transfer and rendezvous both is free,and the optimum index is the least flight time.A Gauss pseudospectral method is chosen to transform the two continuous optimization control problems into nonlinear programming (NLP) problems.After setting up their contact,the two NLPs are solved as two phases of an NLP.As a consequence,comprehensive optimization for orbit transfer and rendezvous can be obtained.Finally,a simulation that verifies the different planes orbit transfer and rendezvous of finite thrust with the impact of perturbation is analyzed through the algorithm mentioned above.The simulation and the obtained outcomes demonstrate that the method is fairly robust,quickly converges and satisfies all the constraints.The method also sets an example for solving this kind of problems.