Development and evaluation of a mobile tire testing device for rolling resistance under varying speed, load, and cone index

Abstract

The increasing use of small- to medium-sized tires in off-road equipment exposes a limitation in existing tire testing protocols designed mainly for larger tires. A Mobile Tire Testing Device (MTTD) was developed that evaluates rolling resistance under controlled soil-bin testing environments. It investigates how forward velocity at 1, 2 and 3 km/h together with vertical load at 885, 1275, 1766 and 2060 N and cone index of 600, 1000 and 1400 kPa affect rolling resistance. Forward speed was adjusted using motor frequency control and gear shifting, while soil conditions were modified through tillage and controlled weight addition. The results demonstrated that rolling resistance increased substantially with increasing load. At a fixed cone index of 600 kPa, rolling resistance increased from 61.3 N at 885 N to 167.2 N at 2060 N, whereas at a higher cone index of 1400 kPa it ranged from 48.5 N to 137.4 N over the same load range. Forward speed produced changes that remained within measurement uncertainty and were therefore not physically meaningful. This study fills an essential testing requirement for tires with diameters under 70 cm and widths under 50 cm by developing a functional testing system to boost tire performance and operational effectiveness in agricultural and construction equipment.