A vehicle with a two-wheel steering system mobile in shallow dense granular media

TL;DR

This paper presents a vehicle with a two-wheel steering system designed to improve mobility and maneuverability in shallow, dense granular media, demonstrating effective resistance reduction and directional control.

Contribution

The study introduces a novel two-wheel steering mechanism for vehicles in granular media, showing enhanced maneuverability and resistance reduction at specific packing densities.

Findings

Steering reduces resistance in dense granular media.

Single-wheel rotation enables vehicle to turn opposite to wheel direction.

Increased contact area improves steering efficiency.

Abstract

We design a vehicle with a steering system made of two independently rotatable wheels on the front. We quantify the effectiveness of the steering system in the mobility and maneuverability of the vehicle running in a box containing a layer ping-pong balls with a packing density 0.8, below the random close packing value 0.84 in 2D. The steering system can reduce the resistance exerted by the jammed balls formed ahead of the fast-moving vehicle. Moreover, if only one of the two steering wheels rotates, the vehicle can turn into the direction opposite to the rotating wheel. The steering system performs more efficiently if the wheels engage the ping-pong balls better by increasing the contact area between the wheels and the balls. We advocate applying our design to machines moving in granular materials with a moderate packing density.