IEEE Access (Jan 2023)

Analysis of Tread ICRs for Wheeled Skid-Steer Vehicles on Inclined Terrain

  • Jorge L. Martinez,
  • Jesus Morales,
  • Jesus M. Garcia,
  • Alfonso Garcia-Cerezo

DOI
https://doi.org/10.1109/ACCESS.2022.3232954
Journal volume & issue
Vol. 11
pp. 547 – 555

Abstract

Read online

The instantaneous centers of rotation (ICRs) for the two treads of skid-steer vehicles moving with low inertia on hard horizontal terrain almost remain with constant local coordinates, which allows to establish an equivalence with differential-drive locomotion. However, this significant kinematic relationship has not been analyzed yet on sloped ground. One relevant difficulty of studying ICR behavior on inclined terrain, even on a flat surface, is the continuous variation of pitch and roll angles while turning. To overcome this problem, this paper analyzes a dynamic simulation of a skid-steer vehicle on horizontal ground where gravity is substituted by an equivalent external force in such a way that pitch and roll are kept constant. Relevant tread ICR variations on inclined ground have been deduced, which have a significant impact on skid-steer kinematics. These new findings have been corroborated experimentally with a four-wheeled mobile robot that turns on an inclined plane.

Keywords