Analysis of tire-road contact area in a control oriented test bed for dynamic friction models

The longitudinal and transversal forces distributed over the tire-road contact area are experimentally analyzed to validate the use of the lumped parameters LuGre dynamic friction model for traction-braking control purposes. To perform the analysis, a test bed based on a scaled quarter vehicle model that consists of a roller, a wheel and a servomotor was designed and built. In this device, the roller represents the road and the vehicle mass, and the tire is directly coupled to the shaft of the servomotor. The distribution of forces in the contact tire-road area is measured by means of strain gages. The obtained results show the distribution of normal forces in the tire-road contact area at different vehicle speeds. They confirmed analytic studies previously reported in the literature regarding the trapezoidal shape of the force distribution in the contact area and also allow to conclude that the lumped parameter LuGre dynamic friction models is suitable for representing the friction forces for traction-braking control purposes.