Scenarios Exploration: How AR-Based Speech Balloons Enhance Car-to-Pedestrian Interaction

Previous studies considered the text-based external human-machine interface (eHMI) as the most effective method for self-driving vehicles. However, classic eHMIs (LED displays, windshields, and grounded projectors) cannot meet these requirements because of various limitations (e.g., placement, space, and limited communication channels). With rapid improvements in the Internet of Things, there are more options to improve communication between self-driving vehicles and pedestrians. We introduce our novel eHMI concept, the AR-based speech balloon, which displays text in a balloon shape and floats around self-driving vehicles through smart glasses. In this paper, we present future research scenarios of people wearing smart glasses. We define the mockups, describe the three main problems, and explain how an AR-based speech balloon can alleviate them in six corresponding scenarios.