Transfer path analysis based on in-situ measurements for automotive applications

Transfer path analysis and synthesis (TPA/TPS) is a widely used approach in the development process of a vehicle which models the transmission from sound sources to a receiver location to identify sources and dominant transfer paths of unwanted noise components. The objectives of this thesis are in-situ transfer path analysis methods for automotive applications which cover the main sources of the driving noise: Powertrain, tire-road contact and wind flow. Different applications require different methods.

The first part contains a TPA method for structure-borne sound induced via elastic elements with an improved prediction quality and which delivers more insight into the transmission behavior. A new approach is presented which determines mount characteristics in-situ from operational data considering the crosstalk on the car body. The effective mount transfer functions are an ideal starting point to estimate parameters of mount models. Physically motivated parameter models with only a few parameters are used to avoid overfitting and, therefore, meaningless values.

In the last few decades engine noise has been reduced continuously, so that the noise generated from rolling tires attracts more and more attention. Further improvements to tire-road noise analysis using on-road measurements are presented. A new approach for the auralization of tire-road interior noise under dynamic driving conditions with a running engine is proposed. This makes it possible to now study the influence of different load and drive torque on the tire-road noise during a run-up.