Autonomous Emergency Braking system for Powered-Two-Wheelers: testing end-user acceptability of unexpected automated braking events deployed in typical pre-crash trajectories

Research question / Starting point for investigation: One of the emerging technologies in road vehicles safety is Autonomous Emergency Braking (AEB), which applies autonomously a braking force to reduce impact speed in pre-crash conditions. Some studies showed that motorcycle AEB (MAEB), could be very effective and reliable in reducing serious consequences of Powered- Two-Wheelers (PTWs) accidents. The main issue before the introduction of MAEB on standard vehicles is related to the acceptability of the system to end-users and the controllability of the vehicle. This study, organized within the EU funded project PIONEERS, wants to assess with common users the acceptability and the controllability of MAEB, deployed in realistic pre-crash scenarios and avoidance manoeuvres. Methods: Field test involved common riders on two test vehicles (a scooter and a tourer motorcycle style) equipped with MAEB functionality. The intervention was triggered in the speed range 35-50 km/h during riding manoeuvres: straight path, lane-change, slalom (meant to mimic traffic filtering), and curve. The participants rode in a circuit; MAEB was activated via remote control unexpectedly at random times. The tested decelerations and jerks were nominally 3 m/s2 and 5 m/s2, and 15 m/s3 and 25 m/s3 respectively. Results: A total of 51 participants took part in the study, each one riding one of the two vehicles; MAEB was activated more than 900 times in different conditions. Participants reported that they were always able to manage the interventions and control the vehicle with minor effort in straight activations and moderate effort in lateral manoeuvres. Impacts / Effects / Consequences: This study investigated the acceptability of MAEB among end-users. Results indicate that the conditions of safe intervention of MAEB may be broader than riding along a straight path. Also, the higher levels of tested deceleration turned out to be safe and acceptable by end-users, suggesting that MAEB intervention could be more effective than what was assessed assuming more conservative decelerations.