TRACTIVE PERFORMANCE ANALYSIS ON RADIALLY DEPLOYABLE WHEEL CONFIGURATION OF LUNAR ROVER VEHICLE BY DISCRETE ELEMENT METHOD

摘要

With the consideration of volume constraint of launch vehicle and trafficability of rover vehicle on lunar regolith terrain,a new design of radially deployable wheel is presented.For the purpose of achieving the meso-mechanics and dynamical behavior of lunar soil particles as well as macro-parameters of tractive performance for radially deployable wheel,the interaction between two types of wheel configurations and lunar soil particles is analyzed by means of discrete element method.The network of contact forces,the displacement vector chart,and the deformation of lunar soil beneath wheels are plotted.The equations of soil thrust,motion resistance,drawbar pull and driven torque are derived in granular scale based on the coordinates transformation and algebraic summation.The calculated results show that there is sufficient traction for both 6-split and 12-split radially deployable wheels with 304 mm outspread diameter to negotiate lunar regolith terrain specified here;the value of drawbar pull enhances with the increase of split number of radially deployable wheel,however,the required driven torque increases simultaneously,therefore,the tractive efficiency decreases.