Performance Evaluation of Wheeled Rover by Analysis and Test

摘要

Rovers provide a mobile platform for exploring planetary bodies. The rover performance on uneven terrain depends on mobility limits on slopes and obstacles which in turn is dictated by the rover configuration. This includes the number of wheels, the dimensions of the rover, wheel size, presence of active joints and the like. In this study, to evaluate the performance of rover on lunar terrain which is uneven and covered with regolith and boulders, benchmark obstacles have been considered that are rigid and regular in shape like inclined and stepped terrain. A quasi-static analysis is carried out where equilibrium equations are solved to obtain the normal contact forces. Subsequently, the friction coefficient required to develop traction to overcome obstacle resistance and the wheel drive torques are obtained. The toppling limits for the longitudinal and lateral directions are also obtained. Consequent to analysis, the rover hardware is tested on benchmark obstacles. To control the rover, an active open loop algorithm has been developed using an external motion controller for the motors used to drive the rover. This study provides a validation to the analytical model besides proving the performance of rover hardware on obstacles.