Tang Jisi, Zhou Qing, Shen Wenxuan, Chen Wentao, Tan Puyuan
State Key Laboratory of Automotive Safety and Energy, School of Vehicle and Mobility, Tsinghua University, Beijing, China.
Front Bioeng Biotechnol. 2023 May 17;11:1176818. doi: 10.3389/fbioe.2023.1176818. eCollection 2023.
Rapidly repositioning finite element human body models (FE-HBMs) with high biofidelity is an important but notorious problem in vehicle safety and injury biomechanics. We propose to reposition the FE-HBM in a dummy-like manner, i.e., through pose parameters prescribing joint configurations. Skeletons are reconfigured along the trajectories inferred from model-specific bone geometries. We leverage differential geometry to steer equidistant moves along the congruent articulated bone surfaces. Soft tissues are subsequently adapted to reconfigured skeletons through a series of operations. The morph-contact algorithm allows the joint capsule to slide and wrap around the repositioned skeletons. Nodes on the deformed capsule are redistributed following an optimization-based approach to enhance element regularity. The soft tissues are transformed accordingly via thin plate spline. The proposed toolbox can reposition the Total Human Body Model for Safety (THUMS) in a few minutes on a whole-body level. The repositioned models are simulation-ready, with mesh quality maintained on a comparable level to the baseline. Simulations of car-to-pedestrian impact with repositioned models exhibiting active collision-avoidance maneuvers are demonstrated to illustrate the efficacy of our method. This study offers an intuitive, effective, and efficient way to reposition FE-HBMs. It benefits all posture-sensitive works, e.g., out-of-position occupant safety and adaptive pedestrian protection. Pose parameters, as an intermediate representation, join our method with recently prosperous perception and reconstruction techniques of the human body. In the future, it is promising to build a high-fidelity digital twin of real-world accidents using the proposed method and investigate human biomechanics therein, which is of profound significance in reshaping transportation safety studies in the future.
快速重新定位具有高生物逼真度的有限元人体模型（FE-HBMs）是车辆安全和损伤生物力学领域一个重要但棘手的问题。我们建议以类似假人的方式重新定位FE-HBM，即通过规定关节配置的姿态参数来实现。骨骼沿着从模型特定骨骼几何形状推断出的轨迹进行重新配置。我们利用微分几何沿着全等的关节骨骼表面引导等距移动。随后，通过一系列操作使软组织适应重新配置的骨骼。形态接触算法允许关节囊在重新定位的骨骼周围滑动和包裹。变形囊上的节点按照基于优化的方法重新分布，以提高单元规则性。软组织通过薄板样条相应地进行变换。所提出的工具箱能够在几分钟内对全身体模型进行安全重新定位（THUMS）。重新定位后的模型可直接用于模拟，网格质量保持在与基线相当的水平。通过展示具有主动避撞动作的重新定位模型进行的汽车与行人碰撞模拟，说明了我们方法的有效性。本研究提供了一种直观、有效且高效的FE-HBMs重新定位方法。它有利于所有对姿态敏感的工作，例如失位乘员安全和自适应行人保护。姿态参数作为一种中间表示，将我们的方法与最近蓬勃发展的人体感知和重建技术相结合。未来，利用所提出的方法构建真实世界事故的高保真数字孪生并研究其中的人体生物力学具有广阔前景，这对重塑未来交通安全研究具有深远意义。
