Measurement of the forces and moments acting on farm tractor pneumatic tyres

A number of experimental activities designed and undertaken for deriving the characteristics of farm tractor tyres are presented. By means of a proprietary measuring hub the three forces and the three moments acting at the hub of a farm tractor wheel have been measured, at different combinations of lateral and longitudinal tyre slips. Tyre steady state characteristics have been derived both on hard asphalt road and on soft soil. The validation of the measurements of tyre characteristics has been performed indirectly by introducing the data referring to tyre characteristics into a detailed mathematical model of a farm tractor. A number of actual manoeuvres have been simulated. The satisfactory agreement between simulated and measured results has provided the necessary condition for the validation of the tyre characteristic measureme nt process.