着陆工况对月球着陆器着陆缓冲性能影响分析

Effects of Touchdown Conditions on the Buffering Performance of the Lunar Lander

复杂的着陆工况对月球着陆器缓冲机构的工作可靠度影响很大。基于典型的四腿式月球着陆器建立月面着陆过程动力学仿真模型,构造了二阶响应面等效分析模型进行敏感度分析,分析了着陆工况各组成因子对着陆器缓冲机构缓冲性能的影响,发现对缓冲性能影响显著的工况因子有足垫与月面摩擦系数、竖直速度、沿z轴方向水平速度、等效月面坡度及绕y轴转角。通过蒙特卡洛模拟研究了工况因子取值对缓冲性能的影响,并通过贝叶斯公式计算了可控着陆工况因子不同取值时的缓冲可靠度。研究发现,采用光滑足垫及降低关闭发动机时着陆器距月面的高度可以提高着陆器的着陆缓冲可靠度。

Complex touch-down conditions have significant effects on the performance of the landing gears in energy absorption. A typical four-legged lunar lander was introduced to build the lunar landing dynamics analysis model and a second order response surface model was introduced to conduct a sensitivity analysis to find out the effects of different landing conditions on the energy-absorption performance. By means of this,high-impact factors such as frictional coefficient,vertical velocity,horizontal velocity along the z axis,equivalent lunar slope angle and rotation angle about the y axis were found. A Monte Carlo simulation was conducted to calculate the landing reliability based on which the reliability analysis with respect to different changeable landing condition values was conducted. It showed that a more smooth footpad and a shorter distant between the lander and the lunar surface could improve the buffering reliability at touchdown.