Research On Adhesive Ability Of Lunar Crater Rover Wheel

Lunar soil sampling and analysis is very significant to study the lunar geometrical structure and the composition of lunar soil.The digging,the hammering and the vertical drilling method are difficult to be used to collect the soil sample which is more than 3 meters deep because of the restriction of the sampling method.Based on the special geometrical structure of lunar crater,a new kind of lunar soil sampling method which can realize the deeper soil sampling through horizontal drilling on the lateral surface of a lunar crater was proposed in this paper.Because of the low gravity and low adhesive ability of lunar soil,in order to successfully collect the lunar soil sample,it is necessary to make sure enough drilling pressure by improving the adhesive ability of rover wheel and lunar soil.Based on the above problem,the adhesive ability of lunar rover wheel was mainly studyed in this paper.The model of lunar crater exploration robot was designed according to the exploration tusk and the limitation of lunar environment,and the model of lunar rover wheel was determined by using the analytic hierarchy process.aiming at the limitation of present static and elastic constitutive model of lunar soil which can't reflect the visco elastic plastic deformation and the time-varying characteristic of lunar soil,the dynamic constitutive model of lunar soil was established according to the particle contact mechanics and the soil rheology.Aiming at the lunar simulant in our lab,the parameters of dynamic constitutive model of lunar soil were got through the joint simulation method of EDEM and ADAMS.The dynamic mechanical model of smooth wheel was established according to the constitutive model of lunar soil,the accuracy of the model was proved by wheel characteristic test.Established the structual parameter model of the surfacial structure of lunar rover wheel,the influence of the parameters of the surfacial structure on the adhesive ability of lunar rover wheel was analyzed by using discrete elment method.Then alalyzed the influence of the normal stress and the shear speed on the adhesive ability of lunar rover wheel,established the adhsive feature model of the wheel according to the simulation results and the dynamic mechanical model of smooth wheel.Established the interaction model of the whole wheel and the lunar soil,analyzed the influence of the speed and the slippage rate on the adhesive ability of lunar rover wheel,the accuracy of the adhsive feature model of the wheel was proved according to the results.Analyzed the influence of lunar characteristics on the adhesive ability of lunar wheel,proving that this kind of wheel has a good adhesive ability on different lunar soil.