山区公路回头曲线车辆横向加速度特性研究

Vehicle Lateral Acceleration Characteristics of Mountain Highway Turning Curve

为了明确车辆在山区低等级公路回头曲线段的横向加速度特性,选择重庆市彭水县境内的一段含有12处回头曲线段的山区公路作为研究对象,开展了20位驾驶员的实车驾驶试验,采集了自然驾驶状态下车辆运行参数,包括速度、轨迹和横向加速度等,分析了回头曲线段横向加速度的幅值特征、变化模式以及峰值位置分布。研究结果表明:车辆在回头曲线段内的横向加速度整体变化特征分为3个阶段:入弯增大阶段、弯中稳定阶段、出弯减小阶段;根据横向加速度85th百分位值的整体变化趋势,将横向加速度划分为4种变化模式;回头曲线段左、右转横向加速度的85th百分位值分别是3.85 m/s^(2)和3.69 m/s^(2),相比一般弯道,驾驶员在回头曲线能容忍更高程度的横向不舒适;车辆在左、右转过程中,每个弯道的横向加速度峰值多集中在曲线中点和圆缓点之间,即圆曲线的后半段。

In order to clarify the lateral acceleration characteristics of vehicles in the turning curve section of low-grade highway in mountainous areas,a section of mountain road with 12 reversing curve sections in Pengshui County,Chongqing was selected as the experimental object,and a driving test of 20 drivers was carried out.The vehicle operating parameters in the driving state,including speed,trajectory and lateral acceleration,etc.,were analyzed for the amplitude characteristics,change mode and peak position distribution of lateral acceleration in the turning curve segment.The results show as follows.The overall variation characteristics of vehicle lateral acceleration in the reverse curve segment can be divided into three stages:increasing stage of entering,stable stage of turning and decreasing stage of exiting.According to the overall change trend of 85th percentile value of lateral acceleration,the lateral acce-leration can be divided into four variation modes.The 85th percentile value of left and right lateral acceleration is 3.85 m/s^(2)and 3.69 m/s^(2)respectively.Compared with the general curve,the driver can tolerate a higher degree of lateral discomfort in the curve.In the process of left and right turns,the lateral peak acceleration of each turn is mainly concentrated between the middle point of the curve and the slow point of the circle,that is,the latter half of the circle curve.