As electric vehicles (EVs) become increasingly common, their quiet operation, especially at low speeds or idle, can make it challenging for pedestrians and other road users to detect their approach. In response, Acoustic Vehicle Alerting Systems (AVAS) have been mandated worldwide to enhance pedestrian safety. Leveraging its expertise in acoustics and HMI products, Kepo has developed a state-of-the-art AVAS solution. From system architecture, sound design, and circuit optimization to comprehensive testing, Kepo
’s AVAS system is designed to meet regulatory standards and ensure road safety.
1. AVAS System Overview
The core function of AVAS is to provide an audible alert when the vehicle is operating at low speeds or in reverse, helping alert pedestrians, especially those less sensitive to quiet electric vehicle sounds. Kepo’s AVAS system is built on a modular design, encompassing high-quality sound synthesis modules, dynamic volume control, and audio amplification modules, ensuring optimal alert performance in all environments. Additionally, the system design prioritizes energy efficiency, employing low-power circuits and intelligent sleep modes, which have minimal impact on the EV’s range.
2. AVAS Audio Circuit Design
Kepo’s AVAS audio circuit is designed with a focus on efficiency and stability, ensuring reliable audio output even under challenging conditions. Key components include:
– Power Amplifier: Featuring Kepo’s proprietary adaptive gain control technology, this amplifier automatically adjusts volume based on vehicle speed and ambient noise, achieving clear sound output while conserving power.
– Power Management: Combining low-power design and intelligent sleep functionality, the system reduces battery drain by entering standby mode when audio output is not required.
– Signal Processing Module: Advanced DSP (Digital Signal Processing) technology optimizes the frequency range and volume of audio output, ensuring the alert sound penetrates external noise and remains consistent.
Through these design innovations, Kepo’s AVAS audio circuit consistently delivers stable, clear audio in various environments, enhancing system reliability.
3. AVAS Sound Design
1. Sound Classification: Kepo’s AVAS system supports various sound classifications tailored to different scenarios. For instance, it includes low-speed driving sounds, reverse sounds, and emergency alerts, adapting to diverse road and operational needs.
2. Sound Processing Capability: Kepo’s system incorporates a high-performance sound processing chip with multi-track parallel processing capabilities. This enables layered audio output for distinct sound alerts, ensuring clarity and audibility in complex environments.
3. Sound Replacement and Updates: The Kepo AVAS system allows for customized sound updates. Users can easily switch sounds to meet the needs of different markets (e.g., regulatory differences). Additionally, Kepo supports OTA (over-the-air) updates to keep sounds current, ensuring compliance with evolving regulations.
4. AVAS Sound Analysis and Regulatory Adaptation
1. Sound Analysis and Design Capabilities: Kepo’s in-house audio design platform offers professional sound analysis software, optimizing sound output across frequency response, loudness, and dynamic range. This proprietary design software enables rapid prototyping of regulation-compliant sounds and provides spectrum analysis and virtual testing at the early stages of development, accelerating the R&D process.
2. Regulatory Compliance: Different countries have specific AVAS sound regulations. For instance, the U.S. mandates minimum dB levels for low-speed alerts, while the EU specifies frequency ranges and loudness requirements. Kepo’s AVAS system includes auto-adaptation functionality, allowing sounds to automatically adjust according to varying regulations, ensuring compliance across regions.
5. AVAS Sound Testing Laboratory
1. Laboratory Capabilities: Kepo’s AVAS sound testing lab is equipped with advanced facilities, including anechoic chambers, environmental simulation devices, and spectrum analyzers. The anechoic chamber eliminates external noise, ensuring testing precision, while environmental simulators replicate diverse road conditions (e.g., urban streets, rural roads), allowing for comprehensive sound performance testing.
2. Testing Procedures: Kepo’s sound testing encompasses crucial metrics like sound penetration, directionality, and clarity. Each sound undergoes rigorous testing to ensure effective performance and reliability under real-world driving conditions.
3. Technical Advantages: Kepo’s AVAS system adheres to stringent testing standards, with each sound carefully crafted to meet or exceed international regulatory requirements. Kepo’s AVAS technology is refined through extensive field testing, ensuring optimal performance across environments, and enhancing both driver and pedestrian safety.
Conclusion
Kepo’s AVAS system not only meets global regulatory standards but also showcases cutting-edge sound design, circuit optimization, and comprehensive testing capabilities. Kepo remains dedicated to innovation, offering safe and reliable sound solutions to meet diverse market needs, advancing safety for electric vehicles, and enhancing road safety.
