A computer simulation model is developed for predicting the dynamic responses of 5, 6, 7 and 8-axle logging truck configurations under different manoeuvres. Simulation can be performed in both the closed-loop and open-loop modes. In the open-loop modes, the time history of either the front axle steer angle or the steering wheel angle (taking into account the compliance of the steering system) is provided as steering input. In the closed-loop mode, the trajectory to be followed by the vehicle is specified and the driver model with optimal preview control is used to calculate the steering input. For the two tested configurations subject to moderate and severe J-turn manoeuvres, discrepancies exist between the prediction of the linear yaw model and the measurements. In contrast, predictions by the present simulation model show better agreement with the measurements. Especially the simulation model is capable of predicting the unstable roll response when the vehicle has reached its rollover limits under a severe J-turn manoeuvre. This demonstrates that the nonlinar type characteristics and various lateral developed simulation models are also used to examine some important performance measures, such as rearward amplification ratio (RWA), load transfer ratio (LTR), transient high-speed offracking (TOF), understeer coefficient (USC), static rollover threshold (SRT), and low-speed friction demand (LFD).
Dynamics of log hauling vehicles
Rechnersimulation der dynamischen Eigenschaften von Langholzfahrzeugen
Heavy Vehicle Systems ; 5 , 1 ; 69-94
1998
26 Seiten, 16 Bilder, 2 Tabellen, 8 Quellen
Article (Journal)
English