Terramechanics-based analysis of slipping and skidding for wheeled mobile robots

Wheeled mobile robots such as planetary rovers are required to traverse over rough and deformable terrain, making obvious longitudinal slip and lateral skid occur to the wheels. Thus new challenges are brought to the control of mobile robots. Wheel-soil interaction terramechanics is the basic theory of analyzing wheel slip and skid. This paper takes the planetary rovers as examples to present the problems of slip and skid caused by rough and deformable terrain. Terramechanics models of wheels moving forward with slip or lateral skid during the process of wheel-soil interaction are introduced. The dynamics models of pure slip, pure skid, and coupling slip-skid of a two-wheeled mobile robot while climbing up, crossing, or crossing and following a straight line are analyzed, respectively. The models are simplified and the disturbances are analyzed on the control design perspective. This study provides basic models of designing control system to compensate slip and skid for mobile robots.