Multi-Physics Simulation Model for Noise and Vibration Effects in Hybrid Vehicle Powertrain 2014-01-2093

Over the past 30 years, simulation of the N&V (Noise and Vibration) behaviour of automotive drivelines became an integral part of the powertrain development process. With current and future HEVs (Hybrid-Electrical Vehicles), additional phenomena and effects have entered the scene and need to be taken into account during layout/design as well as optimization phase. Beside effects directly associated with the e-components (namely electric whistle and whine), torque changes caused by activation/deactivation of the e-machine give rise to vibration issues (e.g. driveline shuffle or clonk) as well. This is in particular true for transient operation conditions like boosting and recuperation. Moreover, aspects of starting the Internal Combustion Engine (ICE) using the built-in e-machine in conjunction with the dynamic behaviour of torsional decoupling devices become increasingly important.

In order to cope with above-mentioned effects a multi-physics simulation approach is required. The following paper proposes a simulation approach that incorporates the domains of the ICE thermodynamics, the mechanical driveline system, the electric components, the vehicle, as well as the fundamental control functions. A special emphasis is put onto non-stationary transient operation, which requires a full coupling between the involved domains. Moreover, the aspect of a combined 1D/3D mechanical modeling is outlined, with the background of scaling model fidelity for components of particular interest and importance (e.g. Dual Mass Flywheel, Centrifugal Pendulum Vibration Absorber, and Gear Stages).

A combination of the AVL's Simulation Tools BOOST RT, CRUISE and EXCITE is utilized for this purpose. The paper outlines the modeling procedure for the different domains, their interaction and coupling and finally shows how different N&V effects can be simulated and evaluated in a comprehensive way.