Two characteristics of terrain mobility are essential in designing an unmanned ground vehicle (UGV): (i) the ability of a vehicle to move through terrain of a given trafficability and (ii) the obstacle performance, i.e., the ability to avoid, interact with and overcome obstacles encountered on a preset route of a vehicle. More attention has been given to the vehicle geometry including selection of the angles of approach and departure, radii of longitudinal and lateral terrain mobility, and the steering system configuration. An essential effect is exhibited by the tire properties in their interaction with the support surface; this, in turn, affects traction properties of the wheel and, thus, vehicle terrain mobility. However, the influence of power distribution between the driving wheels together with vehicle steering system on the two above-listed characteristics of terrain mobility has not been considered in depth.
Unlike earlier studies, this paper presents results of design of an 8×8 unmanned platform to experimentally study vehicle terrain mobility as a function of power distribution between the wheels, steering system configuration, and vehicle re-configurable structural geometry.
The paper demonstrates that the efficiency of the above vehicle design solutions is essentially dependent on the power distribution between the wheels. It is shown analytically and confirmed experimentally that kinematic discrepancy occurs between the wheels; it should be controlled to ensure the proper delivery of power to the driving wheels and improve vehicle surface-support mobility, obstacle performance, and turnability.