Supplementary material for the paper 'I see your gesture: A VR-based study of bi-directional communication between pedestrians and automated vehicles'

Supplementary data for the paper Epke, M. R., Kooijman, L., &amp; De Winter, J. C. F. (2021). I see your gesture: a VR-based study of bidirectional communication between pedestrians and automated vehicles. Journal of Advanced Transportation.<br>Automated vehicles (AVs) are able to detect pedestrians reliably but still have difficulty in predicting pedestrians’ intentions from their implicit body language. This study examined the effects of using explicit hand gestures and receptive external human-machine interfaces (eHMIs) in the interaction between pedestrians and AVs. Twenty-six participants interacted with AVs in a virtual environment while wearing a head-mounted display. The participants’ movements in the virtual environment were visualized using a motion-tracking suit. The first independent variable was the participants’ opportunity to use a hand gesture to increase the probability that the AV would stop for them. The second independent variable was the AV’s response “I SEE YOU,” displayed on an eHMI when the vehicle yielded. Accordingly, one-way communication (gesture or eHMI) and two-way communication (gesture and eHMI combined) were investigated. The results showed that the participants decided to use hand gestures in 70% of the trials. Furthermore, the eHMI improved the predictability of the AV’s behavior compared to no eHMI, as inferred from self-reports and hand-use behavior. A postexperiment questionnaire indicated that two-way communication was the most preferred condition and that the eHMI alone was more preferred than the gesture alone. The results further indicate limitations of hand gestures regarding false-positive detection and confusion if the AV decides not to yield. It is concluded that bidirectional human-robot communication has considerable potential.<br>

本数据集为Epke, M. R.、Kooijman, L. 及 De Winter, J. C. F. 于2021年发表于《先进交通期刊（Journal of Advanced Transportation）》的论文《我看到你的手势：行人与自动驾驶车辆双向交互的虚拟现实（Virtual Reality, VR）研究》的补充数据。<br>自动驾驶车辆（Automated Vehicles, AVs）虽可可靠检测行人，但仍难以通过行人的隐性肢体语言预判其意图。本研究探讨了在行人与自动驾驶车辆交互中，使用显性手部手势与响应式外部人机界面（external human-machine interfaces, eHMIs）的交互效果。<br>26名参与者佩戴头戴式显示器（head-mounted display, HMD），于虚拟环境中与自动驾驶车辆进行交互；研究通过动作追踪服可视化参与者在虚拟环境中的动作。<br>本研究的第一个自变量为参与者是否可通过手部手势提升自动驾驶车辆为其礼让停车的概率；第二个自变量为自动驾驶车辆在礼让时于eHMI上显示的响应语"I SEE YOU"（我已看到你）。据此，本研究对单向交互（仅手势或仅eHMI）与双向交互（手势与eHMI结合）两种场景展开了探究。<br>研究结果显示，参与者在70%的试验中选择使用手部手势。此外，通过参与者的自我报告与手部使用行为推断，相较于未配置eHMI的场景，eHMI可提升自动驾驶车辆行为的可预测性。<br>实验后问卷结果表明，双向交互场景为参与者最偏好的交互模式，且仅使用eHMI的场景相较于仅使用手部手势的场景更受参与者青睐。<br>研究结果还揭示了手部手势存在的局限性：若自动驾驶车辆决定不礼让，可能出现误检与交互混淆问题。综上，人机双向交互具备可观的应用潜力。