N&V Integration and Optimization of Driveline Using Transfer Path Analysis

The automotive manufacturers today have to put more products faster to the market using shorter vehicle development time and also face significant challenges in vehicle design optimisation due to trade-offs mainly caused by increased focus on fuel economy and CO2 reduction. The market expectation on vehicle acoustics refinement is also increasing and plays a significant role in terms of product perception. With extensive introduction of enablers for improved fuel economy, like automated combustion engine stop/start system as well as down speeding/sizing and more aggressive shift maps for automatic transmissions, additional requirements and development tasks are needed for the noise and vibration (N&V) integration of a driveline. The scope of this paper describes the application of transfer path analysis techniques for low frequency driveline excitation at different low engine speed driving conditions focusing on engine start-up/shut-down events. Assessments of advantages and disadvantages as well as subsystem target allocation synthesis are performed. The data and analysis quality and the effectiveness of achieving the customer expected noise & vibration performance, i.e. the remedy selection, depends heavily of methods applied.