The application of external human-machine interface (EHMI) on autonomous vehicles (AVs) facilitates information exchange. Existing research fails to consider the impact of the sequence of actions, as well as the effects of EHMI applications and deception, raising the question of whether benevolent, well-intentioned deception should be permitted (i.e., misleading statements that are intended to benefit both parties). We established a game theory based EHMI information disclosure framework for AVs in this study. In considering benevolent deception, this framework divided the decision-making process into three stages, respectively encompassing three key questions: whether to disclose, when to disclose, and what type of intention information to disclose. The results show that theoretical advantages of deception exist in certain cases when AV expects to maximize the safety of the interaction. In 40 out of 484 cases (8.3%), safety can be enhanced through successful deception. Those successful deceptions fall into two categories: 1) In 28 of these cases, the straight-going AV expected the left-turning human-driven vehicle (HV) to yield, while HV exhibited lower speed and higher acceleration; 2) In 12 of these cases, AV expected HV to proceed first, while HV exhibited higher speed and lower acceleration. We also conducted a VR-based driving simulation experiment, and the results confirmed our conclusion. Additionally, we found that when participants had low trust in the EHMI, its use negatively impacted interaction efficiency instead. This study serves as an exploratory behavioral mechanism study based on specific hypotheses for future EHMI design and ethical decision-making of autonomous driving system.

翻译：自动驾驶汽车（AV）外部人机界面（EHMI）的应用促进了信息交互。现有研究未能考虑行动顺序的影响，以及EHMI应用与欺骗行为的效果，从而引发了一个问题：是否应允许善意的、出于好心的欺骗（即旨在使双方受益的误导性陈述）。本研究建立了一个基于博弈论的自动驾驶汽车EHMI信息披露框架。该框架在考虑善意欺骗时，将决策过程划分为三个阶段，分别对应三个关键问题：是否披露、何时披露以及披露何种意图信息。结果表明，当自动驾驶汽车期望最大化交互安全性时，在某些情况下欺骗行为存在理论优势。在484种场景中的40种（8.3%）情况下，通过成功欺骗可以提升安全性。这些成功的欺骗可分为两类：1）在28种情况下，直行的自动驾驶汽车期望左转的人类驾驶车辆（HV）让行，而HV表现出较低速度和较高加速度；2）在12种情况下，自动驾驶汽车期望HV优先通行，而HV表现出较高速度和较低加速度。我们还进行了基于VR的驾驶模拟实验，结果验证了我们的结论。此外，研究发现当参与者对EHMI信任度较低时，其使用反而会对交互效率产生负面影响。本研究作为基于特定假设的探索性行为机制研究，可为未来EHMI设计及自动驾驶系统伦理决策提供参考。