Handley's low-speed warning sound system AVAS: improving tram road safety

Preface: With the development trend of automobile electrification, the sales of electric vehicles are rising steadily. Market research firm Canalys summarized the global electric vehicle market in 2022 and said that the global electric vehicle sales in 2022 will be 6.5 million units, accounting for 9% of passenger car sales, a year-on-year increase of 109%. However, due to the low noise of electric vehicles, pedestrians, non-motor vehicles and other road users cannot sense the approach of these vehicles (especially vulnerable groups such as the blind or visually impaired), which poses a hidden danger to their safety, especially at road intersections and in specific situations where people with visual impairments walk, the possibility of danger is higher.

To remind pedestrians of the vehicle's sensitive perception when starting and traveling at speed, the Electric Vehicle Low Speed ​​Alert System (AVAS) can emit a simulated engine "buzzing" warning sound when the starting speed is less than 20 km to 30 km.

Taking this situation into consideration, the EU stipulates that from July 1, 2019, all new energy vehicles must be equipped with an acoustic vehicle warning system (AVAS). The regulations stipulate that the AVAS system should be activated when the vehicle speed is below 20km/h, and the minimum sound level is 56 decibels (56dB), which is equivalent to the volume of an electric toothbrush or a paper shredder; the regulations also stipulate that the AVAS sound "should remain continuous to alert other cyclists and pedestrians that a vehicle is passing." For example, changes in simulated engine sound can be used to indicate changes in the vehicle's speed. Many countries have now enacted laws requiring new energy vehicles to install acoustic warning systems, and the number of AVAS installations has increased rapidly.

As the main initiator of the national standard research and development of the electric vehicle low-speed warning sound (GB/T 37153-2018), BESTAR also participated in the formulation of two national standards: vehicle right turn warning sound (GB/T 38694-2020) and reversing alarm. It took 6 years of independent research and development and mastered core technologies. The electric vehicle low-speed warning sound (AVAS) developed by BESTAR is advanced in technology, stable and reliable in performance, long in service life, low in price, and has diagnostic and bootloader functions, which has great value for promotion and use; the DSP solution developed can digitally process key technical parameters such as voice frequency/sound pressure/frequency shift, fully realize the customization needs of sound, and is highly innovative.

BESTAR's independently developed new generation AVAS series product BES-YT0907A-01 has a smaller size and lower cost while maintaining the same overall functions, providing customers with more options.

This series of products is suitable for working environments of -40℃ ~ 85℃, with a waterproof rating of IP67. No matter it is exposed to the sun, rain, cold or freezing, customers do not have to worry about the performance of the product because it is placed outside. In addition, the product has a smart structure and is easy to install in the vehicle. It has at least two or three built-in sound sources to choose from, and can achieve the function of speed-dependent volume frequency conversion. Its design complies with the vehicle speed range, sound level limit, frequency range and sound type required by regulations, and the voltage, function, sound source and sound pressure can be customized according to customer needs.

Nowadays, some European and American countries have installed AVAS on every new electric vehicle, including four-wheelers and two-wheelers. This will encourage AVAS suppliers and automakers around the world to introduce innovative and advanced AVAS. As the sales of domestic new energy vehicles continue to rise, the competition in my country's AVAS industry continues to intensify. AVAS has become a standard component of new energy vehicles, and the prospects are very promising. For automakers, the vehicle low-speed warning sound system (AVAS) can also be used as an expression of brand image.