Single Wheel Field Tester for Farm Tractor Tyres - a Review

Publication Type

Contribution to conference

Authors

Kutzbach, H.D.; P. Witzel und M. Schreiber

Year of publication

2009

Published in

11th European Regional Conference of the International Society for Terrain-Vehicle Systems, CD Publikation

Conference name

11th European Regional Conference of the International Society for Terrain-Vehicle Systems

Conference location

Bremen

Conference date

5.-8.10.2009

The tractive performance of agricultural tractors is depending on traction/slip, lateral force/slip angle characteristics and motion resistance. For the determination of these parameters single wheel testers have been used all over the world to analyse different tyres, surfaces and a whole range of operating conditions. The review gives the state of the art and thereby supports the design of future single wheel testers, which take account for increasing tyre sizes and wheel loads.
To describe the traction/slip relationship gained from experiments with the single wheel tester, e-functions are used most commonly. However, they do not consider the characteristic decay of net traction at higher slip. Therefore, Schreiber extended the e-function by a linear term of the slip. This new equation shows a maximum for the net traction and is defined by four meaningful values. These characteristic values are the x- and y-coordinates of the local maximum (σκmax and κmax), the y-axis-intercept ρe (external rolling resistance) and the gradient of κ at zero slip (κ’(0)).