Investigating the effect of active wheel positioning to develop efficient power saving solutions

Abstract

As the demand for electrically propelled vehicles increases, an emphasis is being placed on power saving techniques. An investigation into the possibility of reducing the energy losses in the tyre of a vehicle during dynamic driving conditions was conducted. The behaviour of the tyre was investigated on component level by means of a tyre drum test rig, which was used to simulate the tyre under various camber and slip angle conditions. A fully validated FTire tyre model was used for the tyre simulations. The tyre simulation results showed a 37.77% reduction in the power loss at a vertical load of 3500N and 56.18% at a vertical load of 6850N by combining camber and slip angle control. These results represent the extreme cases of camber and slip angles. The study was extended to a full vehicle simulation with a MSC ADAMS non-linear full vehicle model that is validated on system level. The FTire tyre model was used for the full vehicle simulations. A camber angle versus lateral acceleration relationship was found and used as inputs for a camber controller. The implementation of the camber controller yielded an energy saving of 4.63% for a constant radius test and 4.41% for a double lane change manoeuvre, when compared to the baseline (pure steering) case. The proposed investigation showed that there exists a possibility to reduce the power losses in the tyres with the use of active wheel positioning.