Target Development for Transmission and E-Motor NVH 2019-01-1554
It is a common practice to conduct NVH fingerprinting and benchmarking assessments at the powertrain level, to understand source level noise and vibration. To assess the NVH influence of engine, e-motor, and transmission, sub-system testing is often con-ducted in addition to full powertrain testing. These powertrain or sub-system investiga-tions provide valuable information regarding the status of “source” level excitations rela-tive to targets and / or competitive powertrains. In the case of transmissions and e-machines, it is particularly important to understand source level tonal content and how this will be perceived at the vehicle level. However, variation in component design re-sults in differences in order content, which complicates the process of objectively com-paring multiple products.
Multiple methods are presented here for characterizing tonal content of transmission and e-machines, based on assessments conducted in a component hemi-anechoic dy-namometer test cell. Ultimately, sound quality is assessed, by the customer, at the ve-hicle level. Accordingly, the methods developed incorporate means of cascading re-sults between component level and vehicle level. Furthermore, since the perception of tonal content is dependent upon the masking noise present, approaches for develop-ment of masking surfaces for both component-level and vehicle-level assessments.
With the information provided by these methods, educated decisions can be made re-garding plans for mitigation of source issues, early in the development process.
Todd Tousignant, Alex Ford, Kiran Govindswamy, Justin Dech, Frederick Vanhaaften, Matthew Hettenhouse
FEV North America, Inc., Ford Motor Company
Noise and Vibration Conference & Exhibition