Power consumption of tracked and wheeled small mobile robots on deformable terrains–model and experimental validation

Abstract

The ability to predict the power consumption of a small mobile robot with either tracked or wheeled configuration is important to its design and control. Accurate and fast prediction of power consumption enables online motion planning that does not exceed the power limits imposed by the propulsion system or the terrain. Skid steering is widely used on small mobile robots because of its simplicity and robust performance. However, modeling of skid steering on deformable terrains is difficult because of the complex vehicle-terrain interaction and the distributed nature of shear stress along the contact surface. This paper first develops a new skid steering model based on terramechanics that is capable of predicting torque and power consumption and is both accurate and computationally efficient. This skid steering model is verified using the experimental data obtained from a track/wheel interchangeable mobile robot driving on dry sand at low speeds. Further, this paper studies the comparison of power consumption between tracked and wheeled mobile robots on deformable terrains focusing on two different aspects: 1) the power losses due to internal friction and damping resistances of both tracked and wheeled configurations, measured from the robot, and 2) the power consumed by deforming the soft soil, using the power consumption model. Overall, this study provides new insights on power consumption of skid steering of both tracked and wheeled mobile robots on deformable terrains.