Communicating the vehicle’s perception and intention to the user

Background: Automated driving functionalities with the goal of fully automated driving are in the research scope of all big OEMs. Automated vehicles (AV) should perform the complete driving task safely by detecting relevant objects and perceiving the driving environment. Due to the shift of control, the role of the driver changes to an on-board user without any driving related tasks. However, the interaction between the AV and its on-board user stays vital in terms of creating a common understanding of the current situation and establishing a shared representation of the upcoming manoeuvre to ensure user acceptance and trust in automation. Method: The presented study investigates two different light-based HMI approaches for AV / on-board user interaction. In a VR-Study 33 (14 female) participants experienced an highly automated left turn drive in an urban environment as an on-board user of an AV. In two different scenarios the AV had do consider either a crossing pedestrian or a vehicle on the oncoming lane. The two HMI approaches (intention- vs. perception-based) were using a 360° LED-Band installed in the interior of the vehicle. Both HMI approaches were compared to a baseline using a within-subject design. Results: Especially in the pedestrian scenario, the two interaction strategies were rated as significantly more trustworthy than the baseline. Additionally, results reveal that using perception- or intention-based interaction design lead to higher usability rating in both scenarios. Conclusions: The developed interaction designs were easy to understand and contained a good level of information richness. Further, both HMI approaches support the information exchange between vehicle automation and on-board user and lead to a significantly higher predictive value of automation behaviour