In order to start working out a proper text for the GTR, various aspects from the Japanese proposal as well as from the NPRM are put together into one document

1. Introduction / Background / Motivation

2. Scope
This standard applies to—
(a) Electric vehicle passenger cars, multipurpose passenger vehicles, trucks, buses, motorcycles, and low-speed vehicles;
(b) Passenger cars, multi-purpose passenger vehicles, trucks, buses, and low-speed vehicles with more than one means of propulsion for which the vehicle’s propulsion system can propel the vehicle in the normal travel mode in reverse and at least one forward drive gear without the internal combustion engine operating and;
(c) Motorcycles with more than one means of propulsion for which the vehicle’s propulsion system can propel the vehicle in the normal travel mode in at least one forward drive gear without the internal combustion engine operating.

3. Definitions [to be determined at a later stage by ISO]

• Broadband sound & content
• Electric/Hybrid Electric vehicle (refer to GRPE subgroup on definitions of vehicle propulsion definitions
• Front plane
• Fundamental frequency
• Rear plane

4. Requirements

4.1. Modes and speeds for activation

4.1.1. The AVAS shall automatically generate a sound at least in the range of vehicle speed up to [20 km/h][30km/h] (not including stationary) and during reversing if applicable for that vehicle category, except prohibited by national/local law.

For vehicles having a reversing sound warning device, it is not necessary for the AVAS to generate a sound during backup

4.1.2. Sound at stationary
The AVAS shall remain deactivated when the vehicle is not moving / at idle / stationary

4.1.3. Start-up sound
When measured according to the test conditions of S6 and the test procedure of S7.2, the vehicle must, within 500msec of activation of its starting system, emit a sound having at least the A-weighted sound pressure level in each of the
one-third octave bands according to Table 1.

4.1.4. ICE engine
In case the vehicle is equipped with an internal combustion engine that is in operation within the vehicle speed range defined above, the AVAS may not need to generate a sound. [further discussion is needed to exactly define the conditions under which AVAS sound is not necessary]

4.1.5. Pause switch / (Timely limited deactivation switch)
If the vehicle emits a synthetic sound to meet the requirements of this regulation, the driver may disable the activation at his discretion. If equipped with pause switch, an indicator shall indicate the deactivation.

The system shall automatically become reactive under the following conditions

4.1.6. The AVAS sound level may be attenuated during periods of vehicle operation.

4.2. Type of sound

4.2.1. The sound to be generated by the AVAS should be a continuous sound that provides information to the pedestrians and vulnerable road users of a vehicle in operation. However, the following and similar types of sounds are not acceptable:

  (i) Siren, horn, chime, bell and emergency vehicle sounds
  (ii) Alarm sounds e.g. fire, theft, smoke alarms
  (iii) Intermittent sound

Note: this paragraph should be deleted as it is not a performance-based description.

4.2.2. At least 2 1/3 octave bands

4.2.3. Each frequency range of [less than 800Hz] and [over 1.25kHz] in 1/3 octave band frequency should exist one or more bands of [xx]dB(A) or more at the vehicle speed of 10km/h and [xx]dB(A) at 20km/h.

4.2.4. For vehicles capable of rearward self-propulsion, whenever the vehicle’s gear selection control is in the reverse position, the vehicle must emit a sound having at least the A-weighted sound pressure level in each of the one-third octave bands according to Table 2 as measured according to the test conditions of S6 and the test procedure of S7.3.

4.3. Pitch shifting

4.3.1. Pitch shift (frequency shift) should be quantified

4.3.2. Pitch shift should have frequency changes of [15%] or more in the range of vehicle speed from 5km/h to 20km/h.

5. Verifying procedures and requirements

5.1. The conditions for the testing incl. tolerances are laid in procedures SAE J2889-1 and ISO 16254
Tests may be carried out in an indoor test facility. In case of indoor testing, a correction of results as function of background is not necessary.

5.1.1. When tested under the conditions of S6 and the procedures of S7.4, the vehicle must emit a sound having at least the A-weighted sound pressure level in each of the one-third octave bands according to Table 3 at any speed greater than or equal to 10 km/h, but less than 20 km/h.

5.1.2. When tested under the conditions of S6 and the procedures of S7.5, the vehicle must emit a sound having at least the A-weighted sound pressure level in each of the one-third octave bands according to Table 4 at any speed greater than or equal to 20 km/h but less than 30 km/h.

5.1.3. When tested under the conditions of S6 and the procedures of S7.6, the vehicle must emit a sound having at least the A-weighted sound pressure level in each of the one-third octave bands according to Table 5 at 30 km/h.

5.1.4.Sounds emitted by AVAS above the regulated speed range
Notwithstanding existing legislation for maximum pass-by noise, there are no requirements for the sound emitted above the regulated speed range.

5.2. Correction of test results
When testing is carried on an outdoor test track, the following correction shall
be applied to the measured values:

In the case of indoor testing, no correction is necessary.

5.3. Directivity

When measured according to the test conditions of S6 and test procedure of S7.2, the sound measured at the microphone on the line CC’ must have at least the A-weighted sound pressure level in each of the one-third octave bands according to Table 1.

It was decided to circulate the draft sketch within the group prior to the next meeting.