Complete Design Development of Control strategy and Rapid prototyping platform for Acoustic Vehicle Alerting System (AVAS). Ravindra Shah, ARAI, India*, Manish Karle, ARAI, India, Pradeep Jawale, ARAI, India, Ujjwala Karle, ARAI, India, Nagesh Walke, ARAI, India KEYWORDS – Pedestrians Safety, Electric Vehicle, AVAS - Acoustic Vehicle Alerting System, model-based control strategy, signal processing, rapid-prototyping, MIL, HIL, Regulatory standards. ABSTRACT Research and/or engineering questions / objective Conventional combustion engine vehicles emit engine sound, even at low travel speeds. Typically, pedestrians and other traffic participants recognize an approaching or departing vehicle through sight and auditory identification of tire sounds and other emitted noise even if the vehicle is out of sight. Electric vehicles (EVs) on the other hand do not have high noise emitting components like combustion engine. These are difficult to hear when travelling at speeds less than 20 Km/h. (At higher speeds sounds from tires becomes dominant.) and thus it calls for introduction of a safety feature that is designed to alert pedestrians, cyclists, and other vulnerable road users to the presence of a silent electric or hybrid vehicle Methodology A detailed market research was carried out to understand about the Acoustic Vehicle Alerting System (AVAS) market, its specifications and features of products available market. AVAS is a device that generates sound signals of rated power and frequency. Based on the UN R138 standard the sound generated must vary in pitch (frequency) and Audio power (dB) depending on the vehicle's speed, so that it provides a clear indication of the vehicle's proximity and direction of travel. One more challenge here was to develop a scalable and configurable rapid proto-typing platform for generating sound signals. Considering the benchmarked specifications, it was decided to build a customized in house rapid-prototyping platform for desired sound generation. The control strategy for AVAS is designed using model-based toolchain and is primarily validated in lab using MIL and HIL toolchain Results The validated control strategy is further deployed on an indigenously developed Audio Rapid Prototyping platform. Finally, the AVAS system is instrumented on an electric vehicle and validation is performed in anechoic sound chamber followed with on road assessment. The results show that the designed system generates audible sound as per regulatory standard UN R138 and AIS 173. What does the paper offer that is new in the field in comparison to other works of the author? The Paper covers a complete development cycle from concept to prototyping to validation on field as per UN regulatory standard R138 and AIS 173 Conclusion AVAS system is designed and developed inhouse that will generate a regulated sound to alert the pedestrians, cyclists, and other vulnerable road users about the presence of Electric vehicles. This system can help to improve safety, reduce accidents, increase visibility, and comply with regulations. The control strategy was designed using model-based toolchain and deployed on a unique rapid prototyping device specially developed for Audio signal processing. This AVAS System so developed meets the requirements as per UN R138 and AIS 173 regulatory standards. The AVAS system is configurable and can be adapted to all category of electric vehicles ranging from a 2-wheeler to heavy commercial vehicle.
Mr. Ravindra Shah, Deputy General Manager, The Automotive Research Association of India