Requirements and testing methods of warning sound for vehicle reversing
1 Scope
This document specifies the terms and definitions, requirements and test methods of warning sound for vehicle reversing.
This document is applicable to vehicles of Categories N2, N3, M2 (with a maximum design total mass greater than 3,500kg), and M3, and other vehicles can refer to it for implementation.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 3785.1 Electroacoustics - Sound level meters - Part 1: Specifications
GB/T 15173 Electroacoustics - Sound calibrators
GB/T 22157 Acoustics - Specification of test tracks for measuring noise emitted by road vehicles and their tyres
GB/T 28046.4-2011 Road vehicles - Environmental conditions and testing for electrical and electronic equipment - Part 4: Climatic loads
GB/T 30038 Road vehicles - Degrees of electrical equipment protection (IP-code)
GB/T 34828 Acoustics - Test methods for the qualification of free-field environments
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
warning sound for vehicle reversing
sound emitted to the area behind the vehicle when reversing, which can prompt other road users
Note: Hereinafter referred to as "warning sound".
3.2
warning sound device for vehicle reversing
a device installed in the specified area of the vehicle to emit warning sounds when the vehicle is reversing
Note: Hereinafter referred to as "warning sound device".
3.3
ambient noise
any other sound perceived by the warning sound device except the warning sound
3.4
non-self-adjusting warning device
a device that emits warning sounds independent of ambient noise
Note: Among the non-self-adjusting devices, Level L indicates only low level, Level N indicates only normal level, Level H indicates only high level, Level I indicates both low and normal levels, Level II indicates both normal and high levels, and Level III indicates all three levels: low, normal, and high.
3.5
stepwise self-adjusting warning device
a warning sound device that can automatically switch between sound pressure levels based on the measured ambient noise.
4 Requirements
4.1 Requirements for warning sound
4.1.1 General requirements
4.1.1.1 The warning sound shall be an intermittent sound, with at least one silent component in each cycle.
4.1.1.2 The warning sound shall be one of the beeping warning sound, broadband warning sound, 1/3 octave warning sound, or voice combined warning sounds.
4.1.2 Requirements for types of warning sounds
4.1.2.1 Beeping warning sound
The continuously played beeping sound emitted by a vehicle while reversing consists of a sound with a main frequency ranging from 1,000Hz to 2,800Hz, played at a frequency of 90 times/min ± 30 times/min.
4.1.2.2 Broadband warning sound
The continuously played broadband sound emitted by a vehicle while reversing consists of multiple frequencies of sound, with a continuous frequency range of at least 1,000Hz to 4,000Hz, played at a frequency of 90 times/min ± 30 times/min.
4.1.2.3 1/3 octave warning sound
The continuously played 1/3 octave sound emitted by a vehicle while reversing has its main energy concentrated in one of the seven 1/3 octaves, with a constant power spectral density within that specific 1/3 octave. The center frequencies of these seven 1/3 octaves are 800Hz, 1,000Hz, 1,250Hz, 1,600Hz, 2,000Hz, 2,500Hz, and 3,125Hz, respectively. The sound is played at a frequency of 90 times/min ± 30 times/min.
4.1.2.4 Voice combined warning sound
The voice combined warning sound consists of voice and one of beeping warning sound, broadband warning sound or 1/3 octave warning sound, and the voice is played after the beeping warning sound, broadband warning sound or 1/3 octave warning sound. The voice is "Reverse, please pay attention", which shall be in clear and legible Mandarin, and the playback frequency is 30 times/min ± 10 times/min.
Contents
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
4.1 Requirements for warning sound
4.2 Requirements for warning sound device
4.3 Requirements for warning sound of complete vehicle
4.4 Type of warning sound
5 Test methods
5.1 Test equipment
5.2 Test site
5.3 Testing method of background noise sound pressure level
5.4 Performance test of warning sound device
5.5 Loading sound pressure level test of warning sound device
