Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden.
Traffic Inj Prev. 2012;13(3):265-77. doi: 10.1080/15389588.2011.649437.
The aim of this study is to model occupant kinematics in an autonomous braking event by using a finite element (FE) human body model (HBM) with active muscles as a step toward HBMs that can be used for injury prediction in integrated precrash and crash simulations.
Trunk and neck musculature was added to an existing FE HBM. Active muscle responses were achieved using a simplified implementation of 3 feedback controllers for head angle, neck angle, and angle of the lumbar spine. The HBM was compared with volunteer responses in sled tests with 10 ms(-2) deceleration over 0.2 s and in 1.4-s autonomous braking interventions with a peak deceleration of 6.7 ms(-2).
The HBM captures the characteristics of the kinematics of volunteers in sled tests. Peak forward displacements have the same timing as for the volunteers, and lumbar muscle activation timing matches data from one of the volunteers. The responses of volunteers in autonomous braking interventions are mainly small head rotations and translational motions. This is captured by the HBM controller objective, which is to maintain the initial angular positions. The HBM response with active muscles is within ±1 standard deviation of the average volunteer response with respect to head displacements and angular rotation.
With the implementation of feedback control of active musculature in an FE HBM it is possible to model the occupant response to autonomous braking interventions. The lumbar controller is important for the simulations of lap belt-restrained occupants; it is less important for the kinematics of occupants with a modern 3-point seat belt. Increasing head and neck controller gains provides a better correlation for head rotation, whereas it reduces the vertical head displacement and introduces oscillations.
本研究旨在通过使用具有主动肌肉的有限元（FE）人体模型（HBM）来模拟自主制动事件中的乘员运动学，以便朝着可以用于综合预碰撞和碰撞模拟中伤害预测的 HBM 迈进。
在现有的 FE HBM 中添加了躯干和颈部肌肉。使用头部角度、颈部角度和腰椎角度的 3 个反馈控制器的简化实现来实现主动肌肉响应。将 HBM 与志愿者在带有 10 ms(-2)减速度的 0.2 s 内的雪橇测试和具有 6.7 ms(-2)峰值减速度的 1.4 s 自主制动干预中的响应进行了比较。
HBM 捕获了雪橇测试中志愿者运动学的特征。峰值向前位移与志愿者的时间相同，并且腰椎肌肉激活时间与一名志愿者的数据相匹配。自主制动干预中志愿者的反应主要是头部小旋转和平移运动。这由 HBM 控制器目标来捕获，该目标是保持初始角度位置。具有主动肌肉的 HBM 响应在头部位移和角旋转方面与志愿者的平均响应的±1 标准差内。
通过在 FE HBM 中实现主动肌肉的反馈控制，可以对自主制动干预中的乘员响应进行建模。对于使用安全带约束的乘员，腰椎控制器对于模拟非常重要；对于使用现代三点式安全带的乘员的运动学则不太重要。增加头颈部控制器增益可以更好地关联头部旋转，而减少垂直头部位移并引入振荡。
