An integrated R&D approach for exterior noise development applying contribution analysis and response modification analysis

The exterior noise is one of the key components in the automotive NVH development process. While strict regulations have to be met, the acoustic character is of major importance for the OEMs. The simulated pass-by is a widely accepted alternative to the real test track, as it is more convenient and independent from environmental conditions. Modifications and additional measurement tasks can be added easily in order to minimize possible sources of disturbances. With the so-called contribution analysis, a ranking of the most common sources, such as intake, engine, exhaust, and tires can be easily performed in addition to the standard measurement. This indicated at which positions modifications might make sense. Nevertheless, the sensitivity of transfer paths is not taken into account, hence sometimes providing an ambiguous conclusion. By integrating the "Response Modification Analysis" into the iterative R&D process, the original signal of the observation can be manually altered. The RMA provides suggestions on which transfer paths are sensitive enough for modifications in order to achieve the alteration of the observation. This way, influences between the individual excitations can be taken into account and possible improvements can be visualized.