Tyre tread estimation from 3D contact patch measurements on the inside of a deformed tyre

This study investigates the feasibility of using measurements of the geometry on the inner surface of a tyre to predict the geometry of the tread on the outside. The proposed method offsets the deformed inner surface along its normal directions by the tread thickness. Initially, a simple 2D cross-section model proved the feasibility of this method. This led to the development of a full 3D tyre model that can estimate the tread of a deformed tyre. Photogrammetry was used to capture a complete 3D geometry model of an unloaded and uninflated tyre, from which the inner and outer surfaces are used to calculate a displacement map for the model. Results indicate that the model can estimate the tread of both a SUV tyre and a large lug agricultural tyre to within about 2.5 mm of measurements of the deformed tread. This tyre is approximately 750 mm in diameter. The remaining error is likely due to the accuracy of the inner and outer surface measurements. The findings pave the way to predict soil volume displacement and contact area, providing crucial insights for vehicle control and mitigating environmental impacts in offroad scenarios. The system is expected to provide extremely useful data for future tyre-terrain interaction research.