山地城市道路交叉口车辆纵向加速度特性分析

Analysis of Vehicle Longitudinal Acceleration at Road Intersections in Mountainous Cities

为明确车辆在山地城市交叉口停车等待到直行通过这一过程中的纵向加速度特性以及驾乘人员舒适性,在重庆市选取4处交叉口作为研究对象。基于无人机航拍的交叉口交通流视频,提取车辆运行状态参数,研究不同坡度交叉口不同停车位次的车辆纵向加速度特性,并以加速度和急动度为指标进行舒适性分析。结果表明:在缓坡路段,停车位次越靠前的车辆其加速度峰值越大;在下坡路段,车辆在加速阶段末段加速度会在0上下波动,车辆间断性的加减速;在上坡路段,第1和第4位次车辆加速度特性相近,加速峰值较大,第2和第3位次加速度特性相近,加速峰值略小;第1停车位次的车辆在下坡减速过程中更容易带来不适感。

In order to clarify the longitudinal acceleration characteristics and the comfort of drivers and passengers in the process of parking and waiting to pass through at mountain city intersections,four intersections were selected as the research object in Chongqing.Based on the intersection traffic flow video captured by unmanned aerial vehicle,the vehicle running state parameters were extracted,the vehicle longitudinal acceleration characteristics of different parking positions at the intersection were studied,and the acceleration and jerk were used as indicators for comfort analysis.The results show these as follows.In the gentle slope section,the higher the parking position,the greater the peak acceleration of the vehicle;in the downhill section,the acceleration at the end of the acceleration phase of the vehicle will fluctuate up and down at 0 m/s 2,and the vehicle will accelerate and decelerate intermittently.In the uphill section,the acceleration characteristics of the 1st and 4th positions are similar,and the acceleration peak is larger,while the acceleration characteristics of the 2nd and 3rd positions are similar,and the acceleration peak is slightly smaller;the first parking position and vehicles are more likely to bring discomfort during downhill deceleration.