着陆姿态不确定下的着陆器缓冲机构优化设计

Optimization Design of a Landing Gear under Uncertain Landing Attitude

以某型着陆器为研究对象,建立其软着陆过程的动力学仿真模型,并结合Monte Carlo法研究不确定着陆姿态下的某型软着陆性能。然后,分析着陆器的软着陆性能与其缓冲机构构型参数之间的相关关系,并基于实验设计方法与动力学仿真模型得到样本点,建立以着陆器缓冲机构构型参数和着陆姿态参数为输入、软着陆性能指标值为输出的响应面模型。最后,基于响应面模型,考虑着陆器姿态的不确定性,运用结合第二代非劣排序遗传算法(NSGA-II)和多岛遗传算法(MIGA)的分级优化方法实现了着陆器缓冲机构的优化计算,得到了最佳缓冲机构构型参数。通过仿真模型校验,优化后着陆器的抗翻倒能力与底面抗损坏能力分别提升了3.546%和5.140%。

A dynamics simulation model for the soft landing process is established with a lander as the research object.The soft landing performance of the lander under uncertain landing attitude is analysed with the Monte Carlo method.Then,the relationship between the soft landing performance of the lander and its landing gear configuration parameters is studied.The response surface models,with the landing gear configuration parameters and landing attitude parameters as input and the soft landing performance index values as output,is established using the samples points extracted by experimental design method and dynamics simulation model.Finally,based on the response model and considering the uncertainty of landing attitude,the landing gear is optimized with the hierarchical optimization method which combines the non-dominated sorting genetic algorithm II(NSGA-II) and multi-island genetic algorithm(MIGA),and the optimum configuration parameters of landing gear is determined.The optimized results are verified by simulation which indicates that the lander’s abilities to resist overturning and to prevent the bottom from being damaged are improved by 3.546% and 5.140% respectively.