Development of Advanced Rider Assistance System (ARAS) for Electric Motorcycles: A Level-1 Collision Avoidance and Emergency Braking Prototype Using Ultrasonic Sensors

This paper presents the design, development, and validation of an Advanced Rider Assistance System (ARAS) tailored for electric motorcycles, with a specific focus on a Level-1 collision-avoidance and emergency-braking prototype employing ultrasonic sensing. The study is motivated by the disproportionately high accident exposure of two-wheeler riders and the slow adoption of ARAS technologies relative to the well-established Advanced Driver Assistance Systems (ADAS) in passenger vehicles. The proposed system utilizes front and rear ultrasonic sensors operating at 40 kHz, offering a measurement range of 2 cm to 4 m with ±1% accuracy, and maintaining reliable performance at motorcycle lean angles of up to 30°. Sensor data are processed using an STM32-series microcontroller running a real-time collision-risk estimation algorithm based on obstacle distance and relative velocity. A configurable safety threshold (typically 3 m) initiates a hierarchical warning strategy comprising visual indicators, acoustic alerts, and haptic cues. If the rider fails to respond within 300 ms, the system autonomously actuates emergency braking through a solenoid-based mechanism capable of modulating deceleration up to 0.6 g to maintain vehicle stability and avoid wheel lock. The ARAS prototype was developed through a structured workflow that included simulation of accident scenarios in IPG Motorcycle Maker, systematic component evaluation, and iterative hardware prototyping. Both simulation and on-road evaluations conducted at operating speeds of 10–40 km/h and various lean angles demonstrated consistent obstacle detection, prompt warning activation, and reliable emergency-braking performance. The system achieved a 92% reduction in simulated rear-end collisions and an average end-to-end response time of 180 ms. The modular system architecture further enables integration of additional sensing modalities and communication interfaces, providing a viable pathway toward higher levels of rider assistance. Overall, the study confirms the technical feasibility and safety benefits of a low-cost ultrasonic-based ARAS for electric motorcycles and establishes a strong foundation for broader deployment and future advancements in two-wheeler safety systems..