Research On Active Soft-landing Stability And Online Decesion-making Method Of Legged-type Lander

The existing landing mode is mainly passive soft-landing,this mode is prone to overturning when landing in complex terrain.In order to improve the landing stability of the lander and meet the lander’s landing needs in complex environments,this paper proposes an active soft-landing concept by adjusting the landing leg attitude and damper damping before landing,and studies the decision-making method in this concept.In this paper,the configuration of the landing leg is analyzed firstly,and the configuration of the inverted triangle is determined for the landing leg.Completed the inverse kinematics analysis of the landing leg.In addition,the mathematical model of the buffer cushioning force and the footpad-soil force is determined,and the model is implemented by the Adams subroutine.An active soft-landing simulation platform was built,and the pre-processing and post-processing functions were implemented by programming.The dynamics calculation kernel uses the Adams/Solver.The pre-processing program can automatically generate a simulation model by the adm language description based on the input parameters.The postprocessing program can automatically evaluate the landing stability according to the key parameters during the simulation process,and the post-processing program realized a 3D visualization interface based on pyqt and pyopengl.Secondly,the variable attitude active soft landing scheme based on aluminum honeycomb damper is studied.The NSGA-II algorithm based on the proxy model is used to optimize the key intrinsic parameters of the lander.The simulation platform and the optimization algorithm based on the complex method are used to optimize the landing parameters under 100 sample conditions.The optimization results show that the active soft landing scheme significantly improves the stability of the landing process.The sample conditions and its optimal landing parameters are used as training sets to train the active soft landing online decision model.The correctness of the model is verified by simulation.Finally,the active soft landing based on magnetorheological damper is studied.The NSGA-II algorithm is used to optimize the inherent parameters of the lander.For the variable damping active soft landing and variable attitude variable damping active soft landing,the landing parameters are optimized under sample conditions.The optimization results show that the variable damping active soft landing has limited stability improvement under sample conditions.The attitude-damping active soft landing has a significant improvement in landing stability.The online decision model was trained for the variable attitude-damping active soft landing scheme.The correctness of the model was verified by simulation.