Net traction force/slip behaviour of tractor tyres - practical oriented measurement and simulation with the Hohenheim Machine Model

Within investigations on the fuel consumption of agricultural process chains, a simulation model for tractors is being developed which enables the calculation of time-related fuel consumption of static operating points. The transmission of forces between tyre and soil in longitudinal direction is mapped by a regression model, which however is based on outdated data. The current status of tyre size and technology can thus only be simulated inadequately. Based on the development and discussion of a suitable measurement methodology to determine the net traction force/slip-curves of modern tyres of larger dimensions, measurements with different tyre sizes are carried out and the results are presented. The introduction of correction factors in the empirical regression equations opens a way to update the tyre-soil model, which is done on the basis of the measured curves. Investigations on the influence of different parameters on the traction behaviour of standard tractors up to 300 kW nominal power are possible with the updated model and are presented as results.