Petermeijer S M, Cieler S, de Winter J C F
Lehrstuhl für Ergonomie, Fakultät für Maschinenwesen, Technische Universität München, Boltzmannstraße 15, 85747, Garching, Germany.
Division Interior, Interior Electronics Solutions, Continental Automotive, Babenhausen, Germany.
Accid Anal Prev. 2017 Feb;99(Pt A):218-227. doi: 10.1016/j.aap.2016.12.001. Epub 2016 Dec 12.
Vibrotactile stimuli can be effective as warning signals, but their effectiveness as directional take-over requests in automated driving is yet unknown. This study aimed to investigate the correct response rate, reaction times, and eye and head orientation for static versus dynamic directional take-over requests presented via vibrating motors in the driver seat. In a driving simulator, eighteen participants performed three sessions: 1) a session involving no driving (Baseline), 2) driving a highly automated car without additional task (HAD), and 3) driving a highly automated car while performing a mentally demanding task (N-Back). Per session, participants received four directional static (in the left or right part of the seat) and four dynamic (moving from one side towards the opposite left or right of the seat) take-over requests via two 6×4 motor matrices embedded in the seat back and bottom. In the Baseline condition, participants reported whether the cue was left or right, and in the HAD and N-Back conditions participants had to change lanes to the left or to the right according to the directional cue. The correct response rate was operationalized as the accuracy of the self-reported direction (Baseline session) and the accuracy of the lane change direction (HAD & N-Back sessions). The results showed that the correct response rate ranged between 94% for static patterns in the Baseline session and 74% for dynamic patterns in the N-Back session, although these effects were not statistically significant. Steering wheel touch and steering input reaction times were approximately 200ms faster for static patterns than for dynamic ones. Eye tracking results revealed a correspondence between head/eye-gaze direction and lane change direction, and showed that head and eye-gaze movements where initiated faster for static vibrations than for dynamic ones. In conclusion, vibrotactile stimuli presented via the driver seat are effective as warnings, but their effectiveness as directional take-over requests may be limited. The present study may encourage further investigation into how to get drivers safely back into the loop.
振动触觉刺激可以作为有效的警告信号，但其在自动驾驶中作为方向接管请求的有效性尚不清楚。本研究旨在调查通过驾驶座椅中的振动电机呈现的静态与动态方向接管请求的正确响应率、反应时间以及眼睛和头部方向。在驾驶模拟器中，18名参与者进行了三个阶段的实验：1）无驾驶阶段（基线），2）驾驶高度自动化汽车且无额外任务（HAD），3）驾驶高度自动化汽车的同时执行一项需要集中注意力的任务（N-回溯）。每个阶段，参与者通过嵌入座椅靠背和底部的两个6×4电机矩阵接收四个方向静态（在座椅的左侧或右侧）和四个动态（从一侧向座椅相对的左侧或右侧移动）接管请求。在基线条件下，参与者报告提示是在左侧还是右侧，而在HAD和N-回溯条件下，参与者必须根据方向提示向左或向右变道。正确响应率通过自我报告方向的准确性（基线阶段）和变道方向的准确性（HAD和N-回溯阶段）来衡量。结果表明，正确响应率在基线阶段静态模式的94%到N-回溯阶段动态模式的74%之间，尽管这些效应在统计学上并不显著。静态模式的方向盘触摸和转向输入反应时间比动态模式快约200毫秒。眼动追踪结果显示头部/眼睛注视方向与变道方向之间存在对应关系，并表明静态振动引发的头部和眼睛注视运动比动态振动更快。总之，通过驾驶座椅呈现的振动触觉刺激作为警告是有效的，但其作为方向接管请求的有效性可能有限。本研究可能会鼓励进一步研究如何让驾驶员安全地重新参与驾驶循环。
