平直高速公路低交通量下L2自动驾驶对驾驶人心理负荷的影响

为研究驾驶人在L2自动驾驶模式下的心理负荷特性,设计了正常驾驶和次任务驾驶2种状态,进行实车高速道路试验,采集21名被试驾驶人在2种驾驶状态下分别选择手动驾驶和自动驾驶模式的眼动数据、次任务绩效和主观评价数据.采用重复测量一般线性模型,分析不同驾驶模式对上述参数的影响,从客观和主观两方面分析驾驶人的心理负荷变化.结果表...

Impact of Level-2 Autonomous Driving Mode on Drivers' Mental Workload Under Low Traffic Volume of Straight Motorway

To explore the characteristics of drivers' mental load in L2 autonomous driving mode, two driving states of normal and secondary task driving were designed, and a real-vehicle test was performed on a straight motorway. The eye movement data of 21 participants, along with performance of secondary tasks and subjective data were collected in manual driving mode and autonomous driving mode. The repeated linear model was used to analyze the influence of different driving modes on the above parameters. The driving workload changes were evaluated from both objective and subjective perspectives. The results show that when drivers perform secondary tasks, the blink duration becomes shorter, blink frequency reduces, and fixation duration on secondary task is longer. While the blink frequency increases, and fixation duration on secondary task reduces significantly when the drivers perform secondary tasks in autonomous driving mode. In addition, drivers are found to pay lesser attention to front road with increased chances of glancing at the dashboard. Moreover, the accuracy of performing secondary tasks is lower and the miss rate is higher. In contrast, when the drivers drive in L2 autonomous driving mode without secondary tasks, the blink duration becomes longer and fixation duration on front road is reduced; more attention is paid to other areas that are unrelated to driving. Additionally, the drivers' physical, temporal, and effort level demands in the autonomous driving mode are lower. The overall subjective perceived mental workload is 85.7% of that in the manual driving mode. However, in the secondary task driving state, no significant difference is observed between the two driving modes. It suggests that executing secondary tasks increases the driving workload, and L2 autonomous driving can reduce the visual load caused by secondary tasks. However, drivers have to switch their attention among front road, secondary tasks, and dashboard, which may increase the cognitive load and reduce the secondary task performance. When there is no visual secondary task, L2 autonomous driving can reduce the drivers' mental workload and difficulty of obtaining information; however, it may also subject the drivers to boredom. In summary, L2 autonomous driving can reduce mental workload under normal driving conditions, but has little effect on mental workload when visual secondary tasks are involved.