Huang Chao, Yang Bo, Nakano Kimihiko
Institute of Industrial Science, The University of Tokyo, Tokyo, 153-0041, Japan.
Accid Anal Prev. 2023 Jun;185:107018. doi: 10.1016/j.aap.2023.107018. Epub 2023 Mar 14.
Safety has become the primary concern of automated driving system (ADS) in recent years. Compared with highly automated driving (L4 and above), conditionally automated driving (L3/L3+ ADS) seems to be a moderate choice, where drivers are required to respond to the takeover request (TOR) whenever necessary. It is the system's responsibility to make sure that the takeovers would be safe at the time of issuing the TOR. To realize that, a lot of factors need to be taken into consideration. As it has been found that drivers' eyes-on-road gazes increase slowly in the first few seconds while transferring to manual driving from automated driving and drivers' gaze behaviors are related with situation awareness, the main aim of this study is to investigate the impact of duration of monitoring before the TOR on takeover time and whether there is a positive or negative relationship between the two. To verify these, we designed a driving simulator study where the TOR was issued 0 s, 5 s, 10 s and ≥ 15 s after the non-driving-related task has ended. Twelve scenarios were designed, and the results from 36 participants showed that there was indeed a statistically significant difference, however, the relationship was neither positive nor negative, which was close to a parabola. Analyzing results of eye movements and gaze behavior further supported this conclusion. It is therefore concluded the duration of monitoring before the TOR should neither be too short nor too long, and 5-7 s would be appropriate choices. This is desirable not only for improving takeover performance of drivers but also for improving the prediction model for predicting takeover performance of drivers that has yet to be studied, so as to improve safety, reliability and acceptance of the ADS.
近年来，安全已成为自动驾驶系统（ADS）的首要关注点。与高度自动驾驶（L4及以上）相比，有条件自动驾驶（L3/L3+ ADS）似乎是一个折中的选择，在这种模式下，驾驶员需要在必要时对接管请求（TOR）做出响应。确保在发出TOR时接管操作是安全的，这是系统的责任。要实现这一点，需要考虑很多因素。研究发现，从自动驾驶转换到手动驾驶的最初几秒内，驾驶员注视道路的目光增长缓慢，且驾驶员的注视行为与态势感知相关，因此本研究的主要目的是探究TOR前的监测持续时间对接管时间的影响，以及两者之间是否存在正相关或负相关关系。为了验证这些，我们设计了一项驾驶模拟器研究，在非驾驶相关任务结束后0秒、5秒、10秒和≥15秒发出TOR。设计了12种场景，36名参与者的结果表明确实存在统计学上的显著差异，然而，这种关系既不是正相关也不是负相关，而是接近抛物线。对眼动和注视行为结果的分析进一步支持了这一结论。因此得出结论，TOR前的监测持续时间既不应过短也不应过长，5 - 7秒将是合适的选择。这不仅有利于提高驾驶员的接管性能，也有利于改进尚未研究的驾驶员接管性能预测模型，从而提高ADS的安全性、可靠性和接受度。
