考虑多种约束的探月飞船跳跃式再入走廊优化设计

摘要

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 .%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。