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 customer perception. Given these new challenges for the sound quality of HEVs, the best approach for learning about perceptions needed to be determined. 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. This report gives a brief overview of a project to deliver this. 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. An interactive HEV model has been successfully created and used in a number of newly created HEV sound quality evaluations. Three assessments were created and carried out which addressed new HEV related refinement issues of varying ICE masking, varying control strategy and the effect of added interior synthesized sound on customer perception. Key findings included: preference for reduced internal combustion engine (ICE) sound in the Toyota Prius and significant differences in perception of the same HEV, over the same drive cycle with varying initial battery state-of-charge (SoC). The process developed and carried out and learning achieved has been documented as a selection of flowcharts and can be used by OEMs or sound specialists as a means for improving HEV sound quality.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:538155 |
| Date | January 2009 |
| Creators | Poxon, John E. W. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/36896/ |
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