Use of System Design Techniques in the Optimization of Integrated Powertrains Incorporating an IVT

Integration of an Infinitely Variable Transmission (IVT) into a vehicle powertrain provides the opportunity to fulfil vehicle attribute requirements via manipulation of many design parameters. To realize this potential the powertrain must be considered as a system that includes the vehicle, the engine, the transmission and the driveline control strategy and calibration. The number of interactions within this system requires that dynamic modeling is used in the analysis of the system. Such an analysis readily provides a route to driveline optimization against any chosen parameter or combination of parameters or metrics.

This paper demonstrates the application of specially written CAE tools and dynamic system modeling analysis during the design and optimization process of an integrated IVT powertrain. This process shows how the vehicle requirements can be met whilst also satisfying constraints imposed by individual elements within the system. The influence and importance of the system calibration upon the IVT transmission packaging will be shown with particular emphasis upon the dynamic requirements of the system.

It is concluded that CAE tools are vital in the full optimization of an IVT integrated powertrain system.