认知分心对车辆跟驰过程操控安全性的影响

为了研究车辆跟驰过程中驾驶人认知分心与驾驶安全的关系，采用驾驶模拟器构建城市道路车辆跟驰场景，并设计3种难度等级的认知分心次任务，采集35名被试驾驶人在试验过程中的方向盘转角、油门开度、制动踏板力等操作参数，以及车辆位置、速度、加速度等车辆运动参数。采用重复测量一般线性模型，分析不同等级认知分心对上述参数的影响。研究结果表明：在横向操控方面，随着认知分心程度增高，方向盘回转率增大，但车辆横向位置标准差减小，表明驾驶人处于认知分心时，采取频繁修正方向盘的补偿方式，降低车辆横向位置波动，过度补偿车辆横向安全性，且该补偿行为与认知分心程度正相关；在纵向操控方面，认知分心时，油门开度、制动踏板位置方差增大，且制动踏板位置均值增大，同时车头间距及时距未观察到显著性变化，表明认知分心时驾驶人采取频繁操作油门、制动踏板，增大制动幅度等方式进行补偿，使车头间距及车头时距等表征车辆纵向跟车安全性参数处于正常驾驶水平，但加速度标准差增大，表明跟车稳定性降低。研究结果为涉及分心的人车交互装置优化设计及考虑分心状态的驾驶人状态管理系统开发提供了一定的理论依据。

Impact of Cognitive Distraction on Vehicle Control Safety in Car-following Situation

To explore the relationship between a driver's cognitive distraction and driving safety during a car-following situation, a car-following scenario on a city road was constructed using a driving simulator, with the design of three different levels of cognitively distracting tasks. The operational parameters (including the steering wheel angle, throttle, and brake pedal position) of 35 subjects, along with the vehicle motional parameters (including the vehicle position, speed, and acceleration), were recorded during the experiment. Repeated measures general linear model was used to analyze the influence of cognitive distraction on these variables. The results indicate that, in terms of lateral control, with an increase in cognitive distraction, the steering reversal rate increases, and the standard deviation of the vehicle's lateral position decreases. These suggest that, when experiencing a cognitive distraction, the driver will move the steering wheel more as a compensatory measure to reduce the variability of the vehicle's lateral position, thereby over-compensating the vehicle's lateral safety; this type of compensation is positively correlated with the difficulty level of cognitive distraction. In terms of longitudinal control, during a cognitive distraction, the standard deviations of the throttle opening and brake pedal position are higher. In addition, the brake pedal position is also higher than the baseline, whereas the following distance and time headway are not significantly changed. These suggest that, when experiencing a cognitive distraction, the driver will operate the throttle and brake pedal more, increasing the braking amplitude, as compensatory measures, as a way to maintain longitudinal safety aspects, such as the distance and time headway, at the same level as under normal driving. However, the standard deviation of the acceleration increases, suggesting decreased longitudinal stability. These results provide the theoretical basis for the design of a human-vehicle interacted device and the development of a distraction-related driver state management system.