Abstract

In order to access the maximum benefits of controlled vehicle braking in reducing ground related injury, based on a basic simulation test sample, which include 24 simulations with three velocities, four pedestrian sizes and two pedestrian gaits, 10176 simulations were conducted by Madymo. After comparative study, we found that the vehicle caused injury will not increase if the vehicle braking is starting to reduce at the time the pedestrian head first contact the vehicle and the ground related WIC/HIC can be maximally reduced 88.9% and 75.6% respectively by controlling the vehicle braking efficiently. Through a further analysis we found that the optimal time at which the vehicle was to fully brake again (t2) is not hard to obtain because the optimal t2 is not an isolated point and hence it is easy to obtain a simple controlling method for a specific car shape but it may be impossible to find one way to control the braking of vehicles with different shapes. And the possible reason that the ground related injury can be reduced is the change of the landing mechanism. Not all ground related injury can be reduced because in some fully braked cases the WIC/HIC is already equal or close to 0; and two danger situations for controlling the vehicle braking were found, which are the pedestrian fall to the ground from the vehicle side and the controlled vehicle cannot contact the pedestrian’s main body in the controlling braking process. Research results will enhance our confidence.

摘要

为了获得受控车辆制动在减少地面相关伤害方面的最大好处，基于基本模拟测试样本，其中包括 24 个模拟，三种速度、四种行人大小和两种行人步态，Madymo 进行了 10176 次模拟。经过对比研究，我们发现如果在行人头部第一次接触车辆时车辆制动开始减少，车辆造成的伤害不会增加，与地面相关的WIC/HIC可分别最大减少88.9%和75.6%有效控制车辆制动。通过进一步分析，我们发现车辆再次完全制动的最佳时间（t2）并不难获得，因为最佳t2不是孤立点，因此很容易获得针对特定情况的简单控制方法汽车形状，但可能无法找到一种方法来控制不同形状车辆的制动。而能够减少与地面相关的伤害的可能原因是着陆机制的改变。并非所有与地面相关的伤害都可以减少，因为在某些完全制动的情况下，WIC/HIC 已经等于或接近于 0；发现了两种控制车辆制动的危险情况，即行人从车辆侧摔倒在地，受控车辆在控制制动过程中不能接触到行人的主体。