Research On Pedestrian Injury And Protection Based On Accident In-depth Study

Pedestrians are vulnerable groups in the road traffics, also belong to theaccident high risk groups. In china, pedestrians killed in road accidents each yearaccounte for a quarter of the total accident deaths. Domestic pedestrian safetyresearch is still in its infancy, especially using the real data to study is even fewer.Therefore, in accordance with domestic actual road traffic conditions, studying themain features of pedestrian accidents, researching pedestrian active and passivesafety technology and reducing the incidence of pedestrian accidents and risks ofinjury or death in the accidents have important social significance.This paper systematically describes the basic processes in the accident in-depthstudy: the scene investigation, the latter survey, accident analysis and database enrty.Collecting and collating284pedestrian accidents data, completing the analysis andreconstruction of the accidents, summarizes the features of pedestrian accidents andpedestrian epidemiology.This paper researches the relationship between sedan frontal structuralparameters and the injuries degree of pedestrian head and lower extremities, in orderto provide guidance for the sedan structural design in favor of pedestrian protection.First, researched the relationship between head contact locations and head injuriesdegree. The study finds head contact locations on windshield frame area, nearwindshield frame area, pure windshield glass area and hood area correspond to thedegree of pedestrian head injuries decreased in turn, head injuries degree increaseswith the increase of head wrap around disrance. Second, researched the relationshipbetween sedan fontal structural parameters and lower extremity injuries. The studyfinds sedan fontal structural parameters have no affect on knee injuries degree,increasing the upper end of the main bumper height from the ground, main and vicebumper width, vice bumper width can reduce shank injuries degree, increasingbonnet leading edge height and distance between the upper end of the main bumperand bonnet leading edge height can reduce thigh injuries degree.According to the frontal shapes of domestic vehicles, this paper divides thevehicle types into long head cars, short head cars and flat cars. Established theregression equations of pedestrian fatality (MAIS3+) risks and impact speed ofdifferent vehicles types. This study finds: the long head cars correspond to thelowest pedestrian MAIS3+and fatality risks, the flat cars correspond to the highestvalues. By comparing the findings from developed countries, the results finds:improving road management, safety awareness of road users and medical standardshave an important role in reducing the pedestrian incidence and casualties risks.According to the motion characteristics of vehicles and pedestrians, this paper establishes mathematical model to study the influence of detection angle, themaximum braking deceleration, braking initiation time and coordination time on theeffectiveness of autonomous emergency braking system to reduce pedestriancasualtyies risks. These have important guiding significance for selecting parametersof autonomous emergency braking system that suitable to the domestic actual roadconditions. The effectiveness at reducing pedestrian fatality (MAIS3+) risks reaches47%(27%) at the detection angle of40°, maximum braking deceleration of0.6g,braking initiation time of1s before impact and coordination time of0.3s.