Experimental Study Of Lightweight Tracked Vehicle Performance On Dry Granular Materials.

This paper presents an experimental study of the performance of a single track device
driving on dry, granular soils. A single-track test rig is used to empirically investigate
track motion under controlled track slip and loading conditions on three
natural dry granular materials:a dry sandy material with 100 um average grain
size, a dry sandy material with 400 um average grain size, and a coarse gravel
with 1 cm average particle size. Test conditions can be designed to replicate typical
field scenarios for lightweight robots, while key operational parameters such
as drawbar force, torque, and sinkage are measured. This test rig enables imposition
of velocities, or application of loads, to interchangeable running gears within
a confined soil bin of dimensions 1.5 m long, 0.7 m wide, and 0.4 m deep. The
tested single track device has an effective contact area measuring approximately
25 cm x 10 cm and it is tested under three vertical loads 125 N, 155 N, and 190 N.
Slip is varied within -50% and +50% during travel over the three soils. The track
utilizes a flexible rubber belt equipped with 0.5 cm tall grousers. Experimental
measurements are compared against well-established semi-empirical models, to
assess the predictive accuracy of these models .