Pedestrian Protection in Low Speed Vehicle-Pedestrian Collisions

在高速(40公里/小时)的碰撞中，行人保护已经得到了大量的研究。在高速碰撞行人保护的基础上，研究了低速碰撞下行人的保护问题，并利用事故数据分析了行人在低速碰撞中的损伤类型和损伤程度。即使在低速碰撞中，行人也可能因头部接触路面或腿部接触保险杠结构而受伤。针对行人头部与路面接触时的损伤风险较高的问题，建立了能够再现行人低速碰撞运动学的多体仿真模型。关节的性能是通过志愿者和身体试验确定的。该模型通过文献中的试验结果和与车辆的投掷距离进行了验证。通过该模型可以看出，在与面包车相撞时，行人可以投射到Vehi…前面增加与路面的接触和接触。特别是当头部接触路面时，伤害可能会很严重。在与厢式车侧面的碰撞中，行人的躯干绕垂直轴旋转，表现出复杂的行为。当面包车的前机头较短时，行人会被抛到引擎盖上，头部坠落在路面上可能会得到防止。此外，还调查了低速碰撞对腿部造成的损伤。在撞击速度为20~40公里/小时的情况下，利用小汽车和腿形撞击器进行了实验研究，结果表明，在高速碰撞速度下表现出相似性能的汽车，其低速碰撞时的肢体损伤风险是不同的。人体有限元分析也被应用于行人与这些汽车的碰撞。这些汽车对行人的伤害风险差异很小，因为伤害参数远远小于胫骨骨折和膝关节韧带断裂的阈值。这一结果表明，在低速车-行人碰撞中，行人头部与路面的接触是最重要的。较少

Pedestrian protection in high velocity collisions (40 km/h) has been investigated in many researches. In the present study, in addition to the pedestrian protection in high velocity impacts, the pedestrian protection at low velocity impacts was examined.Using accident data, the injury types and severities of pedestrian were examined in low velocity collisions. Even in low velocity impacts, pedestrian can be injured due to head contact with road surface or due to lower extremity contact with bumper structures. When the pedestrian head made contact with the road surface, injury risks are high.A multi-body simulation model that can reproduces kinematics of pedestrian in low speed impacts was developed. The joint properties were determined from volunteer and cadaver tests in literatures. This model was validated by test results in references and throwing distance from vehicles. By using this model, it was shown that in a collision with van the pedestrian could be projected in front of vehi … More cle and contact with road surface. Particularly when the head contacts with the road surface, injury can be severe. In the impacts with side of the van type vehicle, the pedestrian showed complex behavior with rotating its torso around vertical axis. When the van has a short front nose, the pedestrian is thrown upon the bonnet and the head falling onto the road surface is likely to be prevented.Injuries to lower extremities in a low velocity impact were also investigated. Experimental tests using cars and legform impactor were carried out with changing impact velocity from 20 to 40 km/h. The injury risks of lower extremities in low velocity collisions were different for cars that show similar performances at high speed impact velocity. The human finite element analyses were also applied for pedestrian collisions with these cars. The difference in injury risks to pedestrian between these cars was small since injury parameters were far smaller than the thresholds of tibia fractures and knee ligament ruptures. From this result, it was demonstrated that the pedestrian head injuries in contact with road surface is most important in low velocity vehicle-pedestrian collisions. Less