Hyundai Motor Company
At moderate to high speeds, the only external noises typically generated by electric vehicles are caused by wind resistance or tire noise. As a consequence, electric vehicles present a risk to pedestrians and cyclists, especially those who are visually or hearing impaired or listening to headphones.
Hyundai active pedestrian alerting system Regulations have been issued in both the United States and the European Union requiring that newly manufactured electric vehicles make an audible noise when traveling at low speeds. These regulations have differing requirements for the amplitude and frequency content of the warning sound.
The simulation results were validated by conducting a 1-volt sine sweep test for both the actual speaker and the simulations. As shown in the figure above, the spectral behavior of sound at 1 meter from the speaker predicted by simulation matches the physical measurements nearly perfectly.
By using Actran to optimize cavity and duct resonances, Hyundai engineers were able to design the speaker to handle low, mid and high frequencies as needed to meet both US and EU regulations while at the same time minimizing speaker size and power consumption. “The simulation results provided by Actran were much more comprehensive than information generated by physical testing, which helped Hyundai engineers quickly iterate to an optimized design in about half the time that would have been required using traditional build and test methods,” Lee said.