用视频方法测量车辆制动减速度问题研究

Research on the Problem of Measuring Car Braking Deceleration Using Video Method

在交通事故处理工作中,有时利用刹车轮胎痕迹长度估算车辆制动初速度,需要知道车辆制动减速度,一般用便携式制动性能测试仪测量,近几年来有人提出可用现场视频进行测量,该方法的测量效果如何,拟通过理论分析和对比实验进行探讨。使用小型乘用车进行紧急制动试验,用便携式性能测试仪采集制动减速度与时间关系曲线,同时在试验车辆侧面放置摄像机录制车辆制动过程影像来测量制动减速度。理论和试验结果分析表明,只有在制动减速度与时间变化曲线的起伏较小和视频方法测量车速误差较小的条件下,用视频方法测量的制动减速度与便携式性能测试仪测量的充分发出平均减速度差异才较小。所以,使用视频方法测量车辆制动减速度时要注意视频条件,仔细分析测量数据,慎重使用。

In the handling of traffic accidents,the initial speed of vehicle braking can be estimated by the length of braking mark.As a result,it is necessary to know the vehicle braking deceleration,which is usually measured by a portable braking performance tester.In recent years,it has been proposed that on-site video can be used for measurement.The measurement effect of this method is to be discussed in this paper through analysis and comparative experiments.During an emergency braking test,a relation curve between braking deceleration and time is plotted by a portable braking performance tester,while braking deceleration is measured by a video recorded by a camera placed on the side of the test car.According to theoretical analysis and practical test,the result of mean fully developed braking deceleration measured by the video method is close to that measured by the portable braking performance tester when the relation curve between barking deceleration and time is relatively stable and the error of car speed measured by video is small.Therefore,when using the video method to measure the car braking deceleration,you should pay attention to the video conditions,carefully analyze the measurement data,and use it with caution.