Research on minimum sound specifications for hybrid and electric vehicles

Details

• Creators:
  Hastings, Aaron ; Guthy, Catherine ; Pollard, John K. ; Garay-Vega, Lisandra
• Corporate Creators:
  John A. Volpe National Transportation Systems Center (U.S.) ; United States. Department of Transportation. National Highway Traffic Safety Administration
• Subject/TRT Terms:
  • Electric vehicles
  • Hybrid vehicles
  • Sound level
  • Pedestrian safety
  • Performance measurement
  • Loudness
  • Pitch (Acoustics)
  • Acoustic emission
  • Sound attenuation
  • Human factors
  More +
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Corporate Publisher:
  United States. Department of Transportation. National Highway Traffic Safety Administration
• Abstract:
  This report documents research by the National Highway Traffic Safety Administration (NHTSA) to identify ways ; to develop sound specifications for electric and hybrid vehicles. The research was conducted to support activities ; related to the implementation of the Pedestrian Safety Enhancement Act of2010. The Pedestrian Safety ; Enhancement Act (PSEA) requires NHTSA to conduct a rulemaking to establish a Federal Motor Vehicle Safety ; Standard (FMVSS) requiring an alert sound for pedestrians to be emitted by all types of motor vehicles that are ; electric or hybrid (EVs and HVs). The goal is to establish performance requirements for an alert sound that allows ; blind and other pedestrians to reasonably detect a nearby EV or HV. The alert sound must not require activation by ; the driver or the pedestrian, and must allow pedestrians to reasonably detect an EV or HV in critical operating ; scenarios such as, but not limited to, constant speed, accelerating, or decelerating. Sound specifications would ; include criteria for sounds to be detectable and recognizable as the sound of a motor vehicle in operation. Two ; concepts to identify potential detectability specifications for alert sounds are explored: (a) minimum sound levels ; based on psychoacoustic modeling and detection distances and (b) minimum sound levels based on the sound of ; internal combustion engine (ICE) vehicles. Potential detectability specifications are discussed in terms offrequency ; range and minimum sound level for selected one-third octave bands. Also considered is the relative proportion of ; acoustical energy emitted from a vehicle as a function of direction (directivity). Recognition includes two aspects: ; recognition that the sound is emanating from a vehicle and recognition of the type of operation that the vehicle is ; conducting. Potential specifications to aid in recognition are discussed in terms of broadband noise and tones (toneto- ; noise ratio) and ways to denote changes in vehicle speed (pitch-shifting as a function of vehicle speed).
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• Format:
  PDF
• Funding:
  DTNH22-ll-V -00063
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/9627/dot_9627_DS1.pdf
• File Type:
  [PDF - 3.56 MB]
• Collection(s):
  Volpe Center
• Main Document Checksum:
  urn:sha-512:93bcdfdbac499b94af4f2551d63191111eda5cd4f48558c1e6a419af0e16b843c7ee3fab94f077168be95231851425d924e65bc38797ad94f7068ea00b1b0292