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The new generation of automatic transmissions is characterized by a compact and highly efficient design. By the use of a higher overall gear ratio and lightweight components combined with optimal gear set concepts it is possible to improve significantly fuel consumption and driving dynamics. Precise and efficient real time models of the whole power train including models for complex subsystems like the automatic transmission are needed to combine real hardware with virtual models on XiL test rigs. Thereby it's possible to achieve a more efficient product development process optimized towards low development costs by less needed prototypes and shorter development times by pushing front loading in the process. In this paper a new real time model for automatic transmissions including approved models for the torque converter, the lock-up clutch and the torsional damper are introduced. At the current development stage the model can be used for comfort analysis and drivability assessment.

High quality predicting of power train vibration behaviour 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.