车辆跟驰安全距离的区间分析方法

摘要

In the car-following process, there are some uncertain parameters in the vehicle brake system and the driver, such as the brake acceleration, the action time of the vehicle arrester and the response time of the driver, etc. Generally, the ranges of these uncertain parameters are easy to be found, but the effect of them on the car-following process is one of the hard issues. This paper used the interval number to describe the uncertain parameters in the car-following process. Based on the approximate computational method of the safety distance, the interval analysis was employed to calculate the safety distance of vehicles under two typical conditions. The results show that the safety distance calculated by the interval analysis method is not a certain value, but an interval value. Therefore, the intervalanalysis method can forecast the effects of the uncertain parameters on the safety distance in the car-following process.%在车辆跟驰过程中,车辆制动系统和驾驶员自身的一些参数均具有一定程度的不确定性,例如车辆的制动减速度、车辆制动器的作用时间及驾驶员的反应时间等.这些不确定量的变化范围通常比较容易确定,然而,如何预测这些不确定量对车辆跟驰行为的影响是目前已有车辆跟驰模型较难以解决的问题之一.文中使用区间数学中的区间数来描述车辆跟驰过程中的车辆制动系统和驾驶员自身参数的不确定性,基于车辆跟驰过程中车辆安全距离的近似计算公式,采用区间分析方法计算了两种典型工况下的车辆安全距离.结果表明,该方法计算得到的车辆安全距离不是确定值而是区间值或者说是一个变化范围,因此能更加真实地预测各种不确定量对车辆安全距离的影响.