Effect of Dynamics on the Stability Index of Tractors

SUMMARY Acceleration can decrease the stability of a tractor and result in a tractor rollover on a moderate slope. This report examines an example of an agricultural tractor rollover on a moderate slope and determines a stability index. Based on stability data and the kinematic analysis of a tractor turning on a slop, the paper modifies the index of static stability based on the steady-state operation of a tractor by introducing a dynamic factor. A tractor rollover was recorded on a video and stability parameters (pitch and roll angles and their rate, as well as yaw rate) were measured by stability sensors. The analysis of the video and stability data in real time showed that the index of tractor stability on a slope is significantly affected by its dynamics (e.g., angle rates and vehicle acceleration). The strong cornering of a tractor wheel and high yaw rate increase the possibility of rollover.