Acoustic vehicle alerting system and method
The invention discloses a method and system for providing an acoustic sound design for an electrified vehicle Acoustic Vehicle Alerting System (AVAS). The method minimizes annoyance from sound leaking into a vehicle compartment. Road and other functional vehicle made sounds (tread noise, fans, wind noise etc.) are used to create an alert sound that mimics these existing vehicle sounds and can be potentially masked, interiorly, by those same sounds. The sounds are recorded and thereafter shaped, amplified and broadcast by speaker(s) placed outside the interior cabin, i.e., one in an engine compartment and another at a rear of the vehicle, so that vulnerable road users can hear the approaching hybrid/electric vehicle. The sound meets jurisdictional requirements in accord with specified frequencies and sound levels. The result is an alert sound perceived as non-irritating and pleasant outside the vehicle, and unobtrusive and background inside the vehicle.
1. A method of creating and providing an alert sound to be emitted by a specified electrified vehicle to fulfil Acoustic Vehicle Alerting System requirements for the specified vehicle, comprising the steps of:
selecting a specified vehicle;
recording exterior operational sounds of the vehicle during electric operation thereof;
subjectively evaluating interior noise frequency spectrum of the specified vehicle based on road noise frequency spectrum for the vehicle when the vehicle is in electrified operation during the recording step;
shaping an exteriorly emitted alert sound of vehicle operational sounds relying on the frequency spectrum of the recorded interior noise is to define optimal frequency bands and level range of the sound emitted from exterior vehicle mounted a first sound emitting unit so as to mimic the frequency spectrum of the recorded interior noise of the specified vehicle; and
emitting those selected and shaped recorded interior sounds from the first exterior sound emitting unit as the alert sound for the acoustic alert system for the specified vehicle so as meet alert sound requirements for that vehicle.
2. A vehicle mounted system for providing an alert sound to be emitted by a specified electrified vehicle to fulfil Acoustic Vehicle Alerting System requirements for the specified vehicle, comprising:
a vehicle;
a first sound emitting unit mounted to the vehicle;
a first recording device for recording exterior operational sounds of the vehicle during electric operation thereof mounted exteriorly to the vehicle;
a second recording device for recording interior operational sounds of the vehicle during electric operation thereof mounted interiorly to the vehicle;
a sound shaping device, having a memory, mounted to the vehicle and electrically connected to the first and second recording devices, for creating and shaping an emitted alert sound of vehicle operational sounds, emitted from the vehicle mounted first sound emitting unit, the sound shaping device relying on a frequency spectrum of recorded interior noise to define optimal frequency bands and level range of the sound emitted from the first sound emitting unit so as to mimic existing frequency spectrum of the interior operational sounds of the specified vehicle; and
a controller, mounted to the vehicle connected to the first sound emitting unit, for controlling the emitting of those selected and shaped sounds from the first sound emitting unit as the alert sound for the acoustic alert system for the specified vehicle so as meet alert sound requirements for the specified vehicle in electric operation.
3. The system of claim 2 , further comprising:
a second sound emitting unit mounted to the vehicle.
4. The system of claim 2 , wherein:
the shaping device further includes pre-recorded sounds of vehicle operation in memory used to augment the emitted alert sound.
5. The system of claim 2 , wherein:
the shaping device further includes predicted sounds of vehicle operation in memory used to augment the emitted alert sound.
6. The method of claim 1 , further comprising:
a second sound emitting unit mounted to the vehicle.
7. The method of claim 1 , wherein:
the shaping device further includes pre-recorded sounds of vehicle operation in memory used to augment the emitted alert sound.
8. The method of claim 1 , wherein:
the shaping device further includes predicted sounds of vehicle operation in memory used to augment the emitted alert sound.