Generalized rigid-body dynamics system simulation and the application to the behavior of suspended agricultural tractors

Abstract

To increase the travel speed and to reduce the vibration of an offroad vehicle, the dynamic behavior of the vehicle must be modified for improving ride comfort. One of the limiting factors to increased operating speeds has been the operator's tolerance to a harsh ride. The vehicle ride quality depends upon the terrain surface roughness, the tractor-implement interactions, the travel speed, and the vehicle geometry and suspension characteristics. The most objectionable levels of acceleration, as experienced by the operator, are in the frequency range 2-10 Hz and are caused by the terrain and the implement loads (Mitschke, 1972; and Soehne, 1965). The vibration frequency should be in the range 1-2 Hz for minimizing resonance and discomfort to the human body. The following design factors, as outlined by Radforth (1978), must be considered for good vehicle ride characteristics: Cab and seat location The operator cab and seat should be configured at a point on the vehicle where the vertical, longitudinal, and lateral vibrations are minimized. The vehicle configuration should take into account the dynamic interaction between the tractor and the implement. Large tires The largest diameter tires should be used for the best ride comfort and obstacle negotiation because they do not follow the rough terrain exactly but filter the terrain profile. The larger wheel has more time to raise the center of the axle by an amount equal to the bump's height Breuer, B. 1975. Automatically controlled hydrostatic transmission for the system vehicle Deutz INTRAC 2006. Automobiltechnischne Zeitschrift 77(4):106-110.