Pedestrian’s Gait,Speed Characteristics And Injury Protection In Human-vehicle Accidents

With the continuous increase in the number of cars in my country,the phenomenon of pedestrian and car mixing is serious,and the pedestrian casualty rate in traffic accidents remains high.Based on the video of 150 real human and vehicle accidents,this paper aims to explore the influence of pedestrian gait in real accidents through simulation and reproduction of accidents,and further analyze the speed characteristics of pedestrians and how to protect against injuries.Based on the real people and vehicles videos accumulated from the research group and collected on the Internet,150 cases of single bicycles and complete collisions were selected,and reconstructed according to the human-vehicle collision reproduction process in the PC-CRASH software,and the accident videos and human injuries were compared.Based on biomechanics,the simulation results are verified.Based on the typical human-vehicle accident data collected in video and simulation,basic information of 150 cases was obtained,and the basic characteristics and typical scenes of human-vehicle accidents were discovered,including pedestrians,vehicles and the environment.Pedestrians in the accident were mainly middle-aged and young people,of moderate stature,with a balanced male-to-female ratio.The collision angle between people and vehicles was vertical,and the collision position was concentrated on the legs.The gait was usually running or walking.However,when pedestrians spotted the vehicle,79.6%of pedestrians spotted the vehicle.Will make an emergency response,that is,emergency gait.The vehicles are mainly cars and SUVs.Most of the vehicles have collision speeds of 20-50km/h.They travel in a straight line and fully brake.59.3%of the drivers’ vision is blocked and the accident is more serious.The vast majority of accidents occurred on straight,flat and dry roads during the day.This summarizes the general laws and phenomena in human-vehicle accidents and lays an important foundation for subsequent research.On the basis of the existing gait research,three pedestrian gait sequences based on real human and vehicle accidents are proposed,and evaluation indicators for distinguishing the three gaits are found,and feature descriptions and parameter definitions are made for the three gaits.The pre-collision state and the state of the pedestrian are redefined.It is found that the speed and height of pedestrians have significant differences between the pre-collision and the time of the collision,especially in the emergency gait,and also in the asynchronous state.The study of gait parameters found that the upper body of pedestrians always leans forward,the limbs are symmetrical,and the difference is obvious in the asynchronous state.The analysis of the pedestrian damage in the asynchronous state in the case shows that the damage basically increases with the speed of the vehicle,and the damage in the asynchronous state is different,and there is no difference in the damage between different models.In order to further explore the influence of gait on human injury and specifically analyze the injury situation of each gait,240 simulation experiments were carried out with model,vehicle speed,pedestrian gait,and speed as test variables.The results show that the damage difference between gait sequences is obvious,and the peak 60%gait and the valley 0%gait are found in the sequence.It is found that the total value of injuries suffered by pedestrians is relatively fixed,and the results are different according to the difference of gait and collision position.In the research on emergency gait,it is found that pedestrians have strong emergency deceleration ability.This leads to an analysis of the speed characteristics of pedestrians.It is found that there is a certain difference between normal walking and pedestrians and the pedestrians in the case,and the speed characteristics of pedestrians are grouped.Sex,variability and contingency.In emergency situations,pedestrians can make full use of acceleration and deceleration capabilities and emergency avoidance to avoid collisions.When they cannot avoid avoidance,they can also consciously and scientifically reduce damage by strengthening their own protection,increasing relative contact with the vehicle,and rolling with their heads.Many results of this research have practical significance for pedestrian injury protection in human-vehicle collision accidents,and also have important theoretical and practical significance in the research and development of vehicle active and passive safety technologies.