Development of a Hybrid Electric Vehicle (HEV) Model for Interactive Customer Assessment of Sound Quality

With the increasing adoption and usage of hybrid electric vehicle (HEV) technologies, there is a growing recognition that attributes such as: dynamics, driveability and refinement can have an adverse affect on customer acceptance. There are a number of new challenges associated with their refinement, in particular their sound quality. These issues include: understanding customers' perceptions of new sound sources, such as electric motor/generators (M/G) and electronic switching devices; reduced masking from the internal combustion engine (ICE); the effect that a more advanced control strategy can have on vehicle-level sound both internally and externally; and the effect of new sound character on driver behaviour and brand perception. Interactive noise, vibration and harshness (NVH) simulation is well suited to further our understanding of these issues. The process for developing models for interactive NVH simulation of conventional vehicles is well established. However, research was necessary to both enhance this process for the creation of HEV models and to create new assessment methods for best-practice use by decision makers involved in the improvement of HEV refinement. This paper gives a brief overview of a project to deliver the former. This project was split into two: the recording phase and the creation and approval phase (to assess the suitability of the HEV model created for jury evaluations). The key stages were: classification of unique HEV operations; development of a HEV NVH model; validation of the NVH model to determine its suitability for interactive simulation; leading onto recommendations for the use of new HEV sound quality models for assessment.