B105 テラメカニクスに基づいた弾性車輪および剛性車輪の力学モデルの提案(OS13 月・惑星探査ロボットの運動と制御1)

Abstract

In this paper, a comprehensive wheel model for both flexible/rigid wheels driving on deformable terrain is developed. The wheel model exploits a terramechanics-based approach with taking account of pressures generated by wheel elasticity as well as terrain stiffness. Deflection of a (semi-) flexible wheel depends on a relative pressure between the wheel and terrain: the wheel will be significantly deformed on rigid terrain whereas it will be hardly/slightly deformed on soft terrain. The wheel-terrain interaction in the proposed model is divided into three contact sections: wheel front section, wheel deflected (flat) section, and wheel rear section. The stress distribution at each contact section is formulated, and then, the traction force of the wheel is obtained as an integral of normal and shear stresses generated at each section. Simulation studies with varied wheel pressures, such as flexible, semi-flexible, and rigid wheels, are conducted to validate the proposed model. Also, traction performances of flexible/rigid wheels are compared based on a metric called tractive efficiency. The simulation results provide an important finding in terms of an optimal wheel pressure of flexible wheel for better traction.