作为典型弱势道路使用者，行人在与汽车碰撞后头部落地碰撞响应呈现高度不确定性，即使碰撞速度较低，头部损伤风险仍然严重，因此具有重要研究意义。本项目拟采集和分析真实的具有视频信息的汽车碰撞行人事故案例，研究行人在与汽车碰撞前/中/后的运动学响应，揭示头部落地碰撞类型和分布规律。基于行人特征、车辆前部结构及碰撞条件，建立多工况的汽车—行人碰撞参数化分析模型，厘清头部落地碰撞速度、角度等与损伤参数的相关性。耦合有限元方法，应用已建立和验证的人体有限元模型重构行人头部落地损伤，揭示碰撞边界物理参数对头部损伤的影响规律，厘清颅脑软组织所受载荷边界条件与脑组织典型损伤评价指标之间的相关性，建立基于真实事故分析的颅脑损伤评价准则。采用区间不确定性多目标优化理论构建头部落地损伤风险控制方程，优化车辆前部结构参数以控制行人头部落地碰撞损伤风险。研究成果可为车辆主动安全条件下的行人头部落地碰撞防护提供理论依据。

As the typical vulnerable road user, pedestrian head-ground impact shows significant uncertain impact configurations in vehicle collision accidents. Moreover, even the head-ground impact velocity is small, the serious head injury risk can occur. The injury prevention of the pedestrian head-ground impact becomes very important. The study aims to analyzing the pedestrian kinematics before/during/after in vehicle collision accidents with video information, to study the head-impact pattern modes and distribution regulations. Developing the parametric pedestrian mulit-body system analysis models under various impact scenarios bases on the pedestrian characteristic, vehicle front-end structure and impact conditions to understand the correlations. Employment of the developed and validated human finite element model to reconstruct the head injuries by head-ground impact based on the real accident, and analyzing the influence of the various type of impact parameters on the head injury mechanism, and studying the correlation between impact conditions between the brain soft tissue loading conditions on the injury criteria of the typical brain soft tissue injuries. Proposing the head injury criteria based on the real pedestrian accident analysis results. Developing the head-impact injury risk control constraint equations using intervals uncertainty multi-objective optimization theory, and optimizing the vehicle front-end structure parameters to control the head-ground impact injury risk in pedestrian accidents. The results from the proposed project can be served as fundamental knowledge to prevention head-ground impact and pedestrian protection in the phase of the active safety conditions.