Longitudinal Skid Terramechanics For Wheels Of Planetary Exploration Rovers

Planetary exploration rovers are playing important roles in space exploration,and the study of wheel-soil interaction mechanics is of substantial importance for aplanetary exploration rover to successfully complete its exploration mission. Skidterramechanics is an important part of wheel-soil interaction mechanics, but hasbeen rarely studied.Experiment is the most direct and effective means to study terramechanics. Aseries of longitudinal skid experiments were taken to learn the mechanics oflongitudinal skid, revealing the wheel configuration parameters, the wheel runningparameters for longitudinal skid experiments and the phenomenon of skid-sinkagewas found. Lay the foundation for establishing a wheel-soil interaction mechanicalmodel for planetary exploration vehicles and provide a basis to judge the discreteelement simulation.Terramechanics model is the foundation of the application of terramechanics. Alongitudinal skid terramechanics model for planetary exploration rovers isestablished based on the longitudinal skid experiments and the traditionalterramechanics model. It is assumed in this paper that there exists a misalignmentbetween the angular position of the maximum radial stress and the angular positionof the transition point of tangential stress, and an improved quadratic model isproposed for calculating the sinkage exponent. The parameters of mechanicalproperty of planetary soil simulant are measured by pressure-sinkage experimentsand shearing experiments. The performance of wheels for plantary explorationrovers is predicted by submiting the mechanical properties parameters of soilsimulant and the measured wheel sinkage into the longitudinal skid mechanicsmodel. According to the comparison between the experimental and simulationresults, it is found that the performance of rover wheels can be accurately predictedusing the proposed model.Discrete element method is a new way of studying terramechanics besidesexperiments. Mechanical model and experiments understand the terramechanicsfrom a macro perspective, however, discrete element mothod from the microscopicpoint. Linear contact model is selected, and soil particals, elastic wheel and rigidwheel are generated using the programming language FISH of PFC3D software.Reference to the DEM (discrete element method) parameters of published literature,the scheme of DEM study is determined using orthogonal experimental design method. Find the influence rule of DEM parameters on longitudinal skidterramechanics.The longitudianl skid terramechanics of wheels for planetary exploration roversis studied using experiments and DEM, respectively. Learnt the longitudinal skidphenomenon and established a longitudinal skid mechanical model for wheels ofplanetary exploration rovers. Lay the foundation for the application of longitudinalskid terramechanics.