Power Train Model Characteristics for Vibration Analyses - Conflicting Demands in Off Line and HiL Environments

摘要

High quality predicting of power train vibration behavior is desired in the early design stage for efficient vehicle development. Conflicting demands arise, since precise, fast simulation models are required. High precision of the models will allow for the elimination of resonance phenomena for future products, thereby ensuring their comfort for the customers. Fast simulations are becoming increasingly important for linking test environments with virtual prototypes under development. This paper deals with different aspects in these conflicting demands for power train vibration models. First, the paper investigates real-time capable mechanical models and decided in favor of the object-oriented modeling approach "for requirements of Hardware in the Loop" (HiL). This paper takes a closer look at the advantages of the object-oriented approach, the model setup, its validation and the test results. A further criterion for the real-time capability is an efficient time integration of the solutions. The result quality of these fast models is then successively compared to offline models as applied in multi-body dynamics (MBD). Even in the low frequency range, the torsional vibrations of the engine are amplified by the vibration characteristics of the power train itself. Therefore, it is essential for the correct simulation of the noise phenomenon to build up precise dynamic models of the parts in the power train, including the areas where the excitation is transmitted to the vehicle body structure. Simulation results are validated with tests of a passenger car power train under operating conditions. The comparison of the different models enhances the specific knowledge for simulation application in the development process.