Evaluation of the Frequency Response of Tractor Cab Angular Movements

The mission profiles of tractors have been modified recently due to a rise in their use as transport vehicles. This use of the tractor together with an increasing maximum velocity on the road emphasizes the containment problem of the vibration transmitted to the driver. In particular, a significant contribution to the increasing global vibration level transmitted to the driver is given by low-frequency movements. Recent work has demonstrated the capability of the ISO standards used for tests in the automotive sector to characterize the dynamic behavior of tractors. In this work, one test, derived from the ISO standards mentioned above, was used to evaluate the capability of the suspension system to isolate the cab from the angular oscillations coming from the driveline. In particular, the frequency response of the cab angular movements was measured on two tractors, with and without an implement connected to the three-point linkage, and was compared with that measured on the tractor's driveline. The results showed a considerable amplification of the roll from the driveline to the cab, particularly with an implement, and a negligible amplification of the yaw.