Experimental and Analytical Investigation of Roller Material Influence on Motion Accuracy of Mecanum-Wheeled Mobile Robots

This study investigates the influence of roller material on the motion accuracy of a Mecanum-wheeled mobile robot. Three roller types were tested: polyurethane rollers from the KUKA YouBot, custom-fabricated rubber rollers, and polypropylene-polyethylene (PP-PE) composite rollers. Experiments were conducted on a flat honeycomb ABS platform under identical control commands and velocity profiles. The results revealed that roller material significantly affects tracking accuracy due to differences in frictional behavior and slip dynamics. The KUKA polyurethane rollers achieved the lowest average forward trajectory error (3.2%) and lateral deviation (2.8%), followed by rubber rollers (5.6% forward, 4.5% lateral), while the PP-PE composite rollers exhibited the highest errors (7.1% forward, 6.3% lateral). A physics-based model incorporating Coulomb friction and rolling resistance was employed to explain these discrepancies, highlighting the roles of surface compliance, material hardness, and contact deformation. This work provides quantitative insight into wheel-ground interactions in Mecanum-wheeled systems, offering guidance for improving motion control precision in mobile robotic platforms.