考虑多种约束的探月飞船跳跃式再入走廊优化设计  

Skip Entry Corridor Design for Lunar Module Considering Multiple Constraints

作　　者：杜昕[1] 李海阳[1] 沈红新[1] 

机构地区：[1]国防科学技术大学航天科学与工程学院,长沙410073

出　　处：《载人航天》2014年第5期443-448,共6页Manned Spaceflight

基　　金：国家自然科学基金(11372345);国家重点基础研究发展计划(2013CB733100)

摘　　要：探月飞船升阻比较低,再入时为达到长的飞行纵程,必须采用跳跃式再入方式。考虑多种约束条件,对跳跃式再入走廊进行了优化设计。首先,对路径约束进行分析,根据跳跃式再入轨迹的动力学特性对轨迹进行分段,推导了关键段中路径约束间的解析关系式,并在此基础上对优化问题进行了简化;其次,对滚转角速度约束进行分析,通过选择合理的离散点个数来保证角速度约束的满足;最后,为保证结果的高精度与全局最优性,采用两层优化策略进行求解,先利用高斯伪谱法得到控制变量初值,再将初值代入直接打靶法中计算得到最终结果。仿真结果表明:路径约束分析结果与优化结果保持一致,可在一定程度上简化优化问题;对滚转角速度约束的处理简单有效;两层优化策略能使问题快速收敛到满足约束的高精度解。For lunar module with low lift-to-drag ratio , skip entry trajectory must be flown to achieve long downrange.In this paper, skip entry corridor was designed considering multi-constraints. First, path constraints were analyzed , analytic relations among them were formulated based on the dynamic feature of skip entry trajectory .Simplification could be made to the original problem .Sec-ond , bank rate and bank acceleration constraints were analyzed .Bank rate constraint could be satis-fied when the number of discrete points was choosing reasonably .Third, considering both the global optimality and high-accuracy of solution , a two-level optimization strategy was proposed .Initial guess of controlled variable was obtained using Gauss pseudospectral method , then the optimal re-sults was obtained using direct shooting .The results indicate that numerical optimization results are in good accordance with the theoretical results of path constraints analysis , the bank constraints en-forcement method proposed in this paper is valid and easy to implement , and the proposed optimiza-tion strategy can obtain high-accuracy optimal solutions which satisfy all the constraints .

关 键 词：跳跃式再入走廊 路径约束 滚转角约束 两层优化策略 

分 类 号：V412.4[航空宇航科学与技术—航空宇航推进理论与工程]