Research on the usability of vehicle dynamics simulation software at FEV Motorentechnik

The goal of this internship is threefold. First there is an assignment to compare two vehicle dynamics simulation software packages, a Simulink two track model provided by the TU/e and a commercial multibody full vehicle model from dSPACE. For this comparison use is made of a chassis tuning project, which is also part of this internship. The TU/e two track model does not contain kinematics and elasto-kinematics, so the preference is given to the dSPACE multibody model. Another nice feature in this package is the possibility for animation of the simulation results. The second project is a hybrid sportscar project. Here the question is two determine which configuration, rear wheel driven or all wheel driven, is the best choice for converting a current sportscar model to a hybrid variant. The decision is based on a test were the vehicle enters a corner at 50 km/h and starts accelerating full throttle at the beginning of that corner. From the results at the exit of the corner can be concluded that the all wheel driven variant is the faster vehicle. Although the traction control system development was a difficult process and a lot of improvements are still possible, the final settings enable the all wheel driven variant to have an exit speed which is 6 km/h higher than the rear wheel driven variant. Here the recommendation is made to optimize the chassis setup for all wheel drive and preferably to use better front tyres. These measures will even further increase the difference and in the simulations the speed difference at the corner exit increases to 15 km/h. The third and final part of this internship was to simulate the influence of an additional battery pack on the dynamic behaviour of a hybrid vehicle. This hybrid vehicle has to be compared with the original vehicle. Measures are taken to decrease this influence and to make the dynamic behaviour of the hybrid vehicle similar to the that of the original vehicle. The influence of adding the additional battery pack is that the unmodified hybrid vehicle is oversteered more and also has some time delay in the lateral acceleration. The measures taken to reduce these effects are adding 0.5 degrees negative camber on the rear wheels, increasing the front roll stiffness with 20% and finally decreasing the rear roll stiffness with 30%. These measures appear to make the hybrid vehicle behave similar to the original vehicle, but real life tests should be performed to check if these measures suffice and if they are feasible with respect to other characteristics (eg. ride comfort).