This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Experiences Tuning an Augmented Power Unit Sound System for Both Interior and Exterior of an Electric Car
ISSN: 0148-7191, e-ISSN: 2688-3627
Published June 13, 2018 by SAE International in United States
Annotation ability available
Event: 10th International Styrian Noise, Vibration & Harshness Congress: The European Automotive Noise Conference
A system for realistic augmentation of power unit sound has been applied to an electric car. Augmented interior sound has been shown to be a powerful enabler for the acceptance and appeal of electric cars. In some territories augmented exterior sound is a legal requirement, to provide a safe urban environment particularly for vision-impaired pedestrians.
An accelerometer located on the electric motor casing provides a live-streamed signal from the power unit that conveys authentic and genuine information. The sound’s level and frequency content are modulated by acceleration demand and vehicle speed signals respectively, thus tapping into the existing ‘language’ of car sound. Inside the car, this enriches the dynamic driving experience during spirited driving, while retaining acoustic comfort under cruising. The sound’s harmonic content can be enhanced and tuned to provide a variety of sonic timbres, reinforcing a wide range of brand and product images, although flexibility is limited to an extent due to the authentic sound source. Outside the car, a balance can be found between informing pedestrians effectively and avoiding environmental noise pollution.
A practical trial-and-error approach has been used to tune the gain map, filter parameters, and other controls. A set of simple tools was developed to support this, including input and output data logging, spectral analysis with order cursors, and simple slope and shape parameterization for the gain map. These tools can be used in the vehicle, enabling quick and interactive tuning of the system to meet interior and exterior sound requirements. Thus, a concise set of candidate sound schemes can be developed, to be presented to senior stake holders for selection.
CitationMaunder, M., "Experiences Tuning an Augmented Power Unit Sound System for Both Interior and Exterior of an Electric Car," SAE Technical Paper 2018-01-1489, 2018, https://doi.org/10.4271/2018-01-1489.
- International Energy Agency, “Global EV Outlook 2016,” 2016, https://www.iea.org/publications/freepublications/publication/Global_EV_Outlook_2016.pdf
- Konet, H., Sato, M., Schiller, T., Christensen, A. et al., “Development of Approaching Vehicle Sound for Pedestrians (VSP) for Quiet Electric Vehicles,” SAE Technical Paper 2011-01-0928, 2011, doi:10.4271/2011-01-0928
- Fortino, A., Eckstein, L., Viehöfer, J., and Pampel, J., “Acoustic Vehicle Alerting Systems (AVAS) - Regulations, Realization and Sound Design Challenges,” SAE Technical Paper 2016-01-1784, 2016, doi:10.4271/2016-01-1784.
- Gillibrand, A., Suffield, I., Vinamata, X., Williams, R., and Brückmann, A., “An Initial Study to Develop Appropriate Warning Sound for a Luxury Vehicle Using an Exterior Sound Simulator,” SAE Technical Paper 2011-01-1727, 2011, doi:10.4271/2011-01-1727.
- Shiosaki, H., Iwanaga, Y., Hideki, I., and Takahashi, Y., “Interior Noise Evaluation of Electric Vehicles - Noise Source Contribution Analysis,” SAE Technical Paper 2011-39-7229, 2011.
- Brandl, S. and Graf, B., “Sound Engineering for Electric and Hybrid Vehicles - Procedures to Create Appropriate Sound for Hybrid and Electric Vehicles,” SAE Technical Paper 2011-39-7228, 2011.
- Sarrazin, M., Janssens, K., Van der Auweraer, H., “Virtual Car Sound Synthesis Technique for Brand Sound Design of Hybrid and Electric Vehicles,” SAE Technical Paper 2012-36-0614, 2012, doi:10.4271/2012-36-0614.
- Poxon, J., Jennings, P., and Allman-Ward, M., “Development of a Hybrid Electric Vehicle (HEV) Model for Interactive Customer Assessment of Sound Quality,” Hybrid & Eco Friendly Vehicles Conference 2008 (HEVC 2008), 2008, doi:10.1049/cp:20081066.
- Genuit, K., “Acoustics of Alternative Drives in the Context of Comfort, Emotion and Brand Differentiation,” 13th Stuttgart International Symposium - Automotive and Engine Technology 2013, 2013, 605-619.
- Engeler, O., Hofmann, M., Mikus, R., and Hirrle, T., “Mercedes-Benz SLS AMG Coupé Electric Drive NVH Development and Sound Design of an Electric Sports Car,” Proceedings 15. Internationales Stuttgarter Symposium, 2015, 1295-1309, doi: 10.1007/978-3-658-08844-6_90.
- Govindswamy, K. and Eisele, G., “Sound Character of Electric Vehicles,” SAE Technical Paper 2011-01-1728, 2011, doi:10.4271/2011-01-1728.
- Maunder, M., Grant, P., and Mawdsley, D., “System for Realistic Augmentation of Sporty Engine Sound Quality,” SAE Technical Paper 2016-01-1781, 2016, doi:10.4271/2016-01-1781.
- Maunder, M. and Munday, B., “System for Augmenting the In-Cabin Sound of Electric Vehicles,” SAE Technical Paper 2017-01-1757, 2017, doi:10.4271/2017-01-1757.
- “Cry Baby: The Pedal That Rocks the World,” Documentary Movie, 2011, Guard House Pictures, Directors: Max Baloian, Joey Tosi,