Dynamic Simulation Study Of Wheel-soil Interaction Under Slope And Multipass For Planetary Rover

The knowledge horizon of humankind has been broadened by the continuous development of deep space exploration.As an important part of planetary exploration,the research on planetary rover has been on the rise in recent years.Because of the low gravity and thin atmosphere,the planetary soil is very loose,which brings many challenges to the planetary rover.In order to avoid the failure of mission,it is necessary to study the wheel–soil interaction of the planetary rover.The climbing ability of the planetary rover is an important index in its passability.When the planetary rover climbs slope,the loose and easy sliding characteristics of soil on the slope are not reflected in the existing terramechanics model.Based on the WongReece model,this paper studied the effect of slope on the wheel-soil interaction normal stress model and shear stress model,introduced the strength reduction method to modify the shear stress model,modeled the wheel-soil interaction dynamics of a single climbing wheel,and compared with the experimental data in the literature for verification.Multi-pass is a necessary module for the motion simulation of planetary rover.As the planetary vehicle usually moves with multi-wheel cooperation,the terramechanics parameters and topographic parameters of soil will change when the wheel repeatedly passes soil,which make the stress state of each wheel change.In order to develop simulation module for the vehicle multi-pass,through the study of the wheel-soil interaction normal stress model and shear stress model,the contact model of multi-pass was deduced and the multi-pass contact algorithm was discussed.Combined with the mathematical model of the climbing and the multi-pass,the corresponding program is compiled and added to the developed vehicle motion simulation platform.Based on the MSC.Adams software,the dynamic model of the planetary vehicle is established and the simulated analysis is made on the rover model such as climbing slope,multi-pass and natural terrain simulation.In the end,the passing performance of the whole vehicle is evaluated.