Abstract
Many researches on vehicle-road interaction are performed without taking into account the response of the road profile (surface). However, these signals providing from road are very important in the vehicle dynamics, since they contribute to generate the contact tire forces of heavy vehicles. We show in this paper, the influence of the road profile in the heavy vehicle modelling. In this work, we propose a method to evaluate these vertical forces based on modification of the super twisting algorithm. This technic is very much used for the dynamic systems and the results of various research are very satisfactory. Design of such observers requires a dynamic model. Then, we develop a heavy vehicle model in interaction with road (this road profile is considered as inputs of the heavy vehicle model). In a validation procedure, we compare simulation results coming from a developed heavy vehicle estimator and responses done with the PROSPER´s simulator which has been validated with numerous experiments on proving ground. When the vertical forces are finally estimated, we can calculate the LT R (Load Transfer Ratio) coefficient to evaluate the rollover risk.
Keywords:Heavy vehicle modelling, road profile, vertical forces, rollover, second order sliding mode observer.