Refinement of vehicle interior noise by reduction of driveline vibrations.

Driveline vibrations can be a significant vibration source, which require emphasis in vehicle NVH development studies. In the early design phases, it is usually not easy to predict the vehicle level NVH performance induced by the torsional irregularities of the driveline. Establishing a model with inertia, mass, and stiffness data taken from engine, transmission and driveline suppliers can be possible and useful to initiate preliminary cautions. However, it is first, a challenging job for OEMs to receive all relevant data from suppliers to create a reliable model. Second, driveline vibration-driven NVH response of a vehicle is mostly figured out in real-time testing. Therefore, it is of great importance to treat driveline vibrations as a potential source of customer concern in vehicles and should be investigated throughout the testing phase. In this study, a dissatisfying noise behavior of a coach is determined with objective data and defined by means of engine operating condition, frequency, and excitation orders. As a next step, the problem is cascaded to its possible sources by examining the exciters’ inputs and the transfer paths. Finally, the important parameters in the reduction in driveline torsional vibrations and, as a consequence, the refinement of vehicle interior noise are discussed.