Available at: https://digitalcommons.calpoly.edu/theses/2328
Date of Award
MS in Electrical Engineering
College of Engineering
College of Engineering
As autonomous vehicles become more prevalent in urban traffic settings, the safety of vulnerable road users, predominantly pedestrians, must be placed in high regard relative to the design of the autonomous vehicle's (AV's) external human machine interface (HMI). Traditionally, there exist communication methods between drivers and pedestrians, such as hand gestures, eye contact, and verbal cues that convey the driver's awareness of the pedestrian's presence. However, with autonomous vehicles, there is a shift in communicative responsibility from the driver to the vehicle itself. It is the vehicle's responsibility to intuitively and clearly indicate its actions to the pedestrian.
This research analyzes the factors contributing to AV skepticism and the ways in which the visual aspect of an AV's external HMI can be improved from traditional vehicle designs to accommodate visually impaired pedestrians. This was achieved by performing a study on 27 participants varying in age, gender, and vision impairment type. The study includes a survey and interview portion. Findings indicate that yellow and blue colors are viewed as most welcoming and memorable. It is suggested that these colors be used in the projected light system of the external HMI design. Quantitative results indicate that there is a moderate degree of correlation between the following: the use of cruise control and vision impairment severity (negative correlation), a participant's willingness to ride in an AV and vision impairment levels (positive correlation). The study also found a low degree of correlation in a participants willingness to ride in an AV and their trust in AVs.
Based on these findings and under the assumption than an external HMI is needed on the AV, it is recommended that the external HMI contain a light projection system on the vehicle's front body. Based on qualitative results, the light projection system should use a teal color light and project a directional arrow onto the ground when identifying a pedestrian in its path while turning. Intuitive signals such as these help ensure pedestrian safety and promote trust and acceptance of the use of autonomous vehicles on public roads.