Audi developing e-sound for EVs
05 April 2012
Audi is developing e-sound, a synthetic sound generation system for its e-tron electric vehicles to ensure that pedestrians in urban settings will hear them.
In a series-production Audi, a combustion engine currently supplies the car’s sound. Conversely, the motor in an electric-powered e-tron is not an option, as it is too quiet and its high frequencies are not melodious. Audi’s e-tron models will therefore feature a synthetic sound signature. Rudolf Halbmeir, an acoustics engineer, teamed up with his colleagues Axel Brombach and Dr. Lars Hinrichsen to create it. The e-tron itself generates its sound.
Data relating to the electric motor’s rotational speed, vehicle speed, loads, and other parameters is continuously supplied by the vehicle to the control unit. It then uses this data to generate sound.
—Dr. Lars Hinrichsen
The e-sound is played via a sturdy loudspeaker attached to the car’s undercarriage. Audi designed the loudspeaker to handle as much as 40 watts, but during normal operation it ranges between five and eight watts—loud enough for nearby pedestrians and cyclists to hear the e-tron. A fraction of the sound signature enters the vehicle’s interior via airborne and structure-borne sound waves.
Each Audi e-tron model will have a unique sound signature.
A kneejerk Congressional overreaction to an imagined problem:
"The [2010] Pedestrian Safety Enhancement Act mandates a rulemaking to establish a standard requiring electric and hybrid vehicles to be equipped with a pedestrian alert sound system that would activate in certain vehicle operating conditions to aid visually impaired and other pedestrians in detecting the presence, direction, location, and operation of those vehicles."
NHTSA is planning to require ICE sounds to be played by slow-moving BEVs. Nicer sounds, in their opinion, would not scare away unwary pedestrians, and Congress no doubt assumed that drivers will not be paying attention to where they are headed (texting, etc?). It's not like drivers of ICE vehicles never hit pedestrians.
One of the attractions to BEVs is that they are quiet. I for one will be disconnecting the mandated noisemaker when I get my BEV.
Posted by: ChrisL | 05 April 2012 at 11:08 AM
Congress passed legislation in 2010 that told the National Highway Safety and Transportation Administration to develop regulations for ICE sounds to be played by electric cars -- a kneejerk overreaction to a dubious problem.
"The Pedestrian Safety Enhancement Act mandates a rulemaking to establish a standard requiring electric and hybrid vehicles to be equipped with a pedestrian alert sound system that would activate in certain vehicle operating conditions to aid visually impaired and other pedestrians in detecting the presence, direction, location, and operation of those vehicles."
NHTSA has said the sound will model an ICE, as they believe a more pleasant noise might not alert pedestrians. It's not as if drivers of ICE vehicles never hit pedestrians, however. Shouldn't the government assign some responsibility to drivers to avoid hitting potential victims? What about pedestrians listening to their iPods? How will an artificial engine sound solve that problem?
One of the attractions of BEVs is their quiet. I, for one, will be disconnecting the noisemaker when I get my BEV.
Posted by: ChrisL | 05 April 2012 at 11:22 AM
What a breakthrough.
Posted by: ToppaTom | 05 April 2012 at 08:31 PM