基于自然驾驶数据的螺旋匝道(桥) 驾驶人心理负荷分析

为得到驾驶人在螺旋型立交匝道路段行车时的驾驶负荷及影响因素，选取4 座山地城市螺旋型立交开展自然驾驶实验，利用车载仪器采集自然驾驶习惯条件下的驾驶人心电信号. 分析心率幅值特征、心率连续差异均方根( RMSSD )整体分布特征，以及其与匝道半径、坡度之间的关系. 结果表明，影响心理负荷的主要因素是车辆行驶环境和匝道曲率变化. 匝道的分、合流鼻端处，以及行车过程中跟车、超车和会车均会使驾驶人心理负荷增大，驾驶人行驶在上坡路段的紧张感高于下坡路段，匝道半径与RMSSD 存在较强的负相关性. 纵坡坡度与心率变异指标之间呈现两种不同的相关关系：不熟练型驾驶人随着坡度增加，RMSSD 呈线性上升的趋势；一般型和熟练型驾驶人表现为中间高两边低的趋势.

Analysis of Driver Mental Load on Helical Ramps and Helical Bridges Based on Naturalistic Driving Data

To analyze drivers' mental load and the influencing factors when driving on the helical ramps and helical bridges, field driving tests using real passenger cars were conducted on four interchanges in a mountain city. The driver's ECG signals under the natural driving habits were collected by onboard instruments. Based on this naturalistic driving data, the relationship between heart rate amplitude, the RMSSD index overall distribution, and the ramp radius and slope were analyzed. The results indicated that the driving environment and horizontal curvature of the ramp, as well as the on-ramps junction and diversion, are the main factors of the mental load. The following, overtaking and meeting in the driving process all increase the driver's mental load. The driver's nervousness is higher when they are driving on uphill ramps than that on the downhill ramps. There is a strong negative correlation between the ramp radius and heart rate variability. Moreover, the unskilled driver is the most sensitive to the change of the ramp radius. There are two different correlations between ramp gradient and the heart rate variability: for unskilled drivers, the RMSSD increases linearly as the slope increases, while for the general and skilled drivers, their RMSSD profiles have a trend of high in the middle and low on both sides.