Abstract
A systematic modelling approach to vehicle dynamics simulation, validation and optimization is presented using an effective link between a multibody solver and a mathematical analysis package. In particular, a heavy vehicle tractor/trailer combination which is common on European roads is modelled and evaluated on handling and roll-over for various loading configurations.
Using geometric and inertia information, as well as measured data from standard ISO lane change and pseudo-random driving tests, a vehicle model was developed in MADYMO and validated in stages; the influence of various parameters on the overall response of the vehicle was examined in terms of the calculated transfer function. Tyre behaviour was characterized using a pragmatic model based on the so-called Magic Formula, and extensive use was made of the data processing and evaluation features of MATLAB during validation. The addition of a path following driver model further enhanced the scope of the simulation.
The combination of a multibody model with a mathematical analysis tool proved to be an efficient and versatile environment for vehicle dynamics analysis. The analysis and comparison of test and simulation data in the frequency domain significantly streamlined the validation process and provided greater insight into the effect of various vehicle parameters on the overall response of the tractor/trailer combination.
The tractor/trailer model has been used to get some idea on the influence of the drivers reaction time and trailer loading on roll-over behaviour. It seems that driver reaction time has less influence on the occurrence of roll-over accidents than differences in loading type (fixed versus hanging loads).