Brynskog Erik, Östh Jonas, Larsson Karl-Johan, Iraeus Johan
Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, Sweden.
Volvo Cars, Gothenburg, Sweden.
Front Bioeng Biotechnol. 2025 Jul 9;13:1570572. doi: 10.3389/fbioe.2025.1570572. eCollection 2025.
In future autonomous vehicles, a greater seat back recline angle has been suggested to accommodate a more relaxed occupant position. Due to the reclined position, the pelvis rotates rearward resulting in less favorable in-crash pelvis to lap belt interaction. In a crash, this issue can increase the likelihood of the lap belt disengaging from the pelvis and instead loading the abdomen, , submarining. Hence, to enable assessment of submarining prevention measures for reclined occupants in frontal car crash scenarios, it is motivated to enhance the understanding of pelvis to lap belt interaction.
In this simulation study, the submarining outcome of a population of reclined 50%ile (in terms of height and weight) male occupants, subjected to restraint variability in a semi-rigid seat setup, was analyzed through finite element human body model (FE-HBM) simulations (n = 369). To account for the substantial individual variability associated with pelvic shape, a statistical shape model was utilized to predict a large set of random 50%ile male pelvises. Based on select measurements, a sub-sample was drawn from this set (n = 78) for inclusion in the analysis. The simulated submarining outcome and corresponding occupant/restraint parameters were used to generate a metamodel predicting probability of submarining.
The results showed that random variations of a 50%ile male can be comparable with restraint design variability on submarining outcome for reclined occupants. Significant predictors included three from the occupant (pelvis angle, iliac spine hook angle, and H-Point forward/rearward position), and three from the restraint (buckle angle, seat friction, and seat pan angle). Non-significant predictors included occupant soft tissue thickness and fat stiffness, shoulder belt load limit force, and inclusion/exclusion of single lap belt pre-tensioning.
In conclusion, this study implies that future vehicle safety ratings, using different versions of a 50%ile male FE-HBM, may be subject to variation in submarining outcome if harmonization of the target occupant anatomy/posture is not established. In addition, based on the response in a semi-rigid seat setup, this study also indicates that to achieve robust submarining protection for reclined occupants, the current legal requirements on buckle angle might need a shift towards more vertical angles.
在未来的自动驾驶车辆中，有人建议增大座椅靠背倾斜角度，以适应更放松的乘客姿势。由于处于倾斜位置，骨盆会向后旋转，导致碰撞时骨盆与安全带的相互作用变得不利。在碰撞中，这个问题会增加安全带从骨盆脱离而改为压迫腹部的可能性，即“滑下”。因此，为了能够评估在正面汽车碰撞场景中针对倾斜乘客的防滑下措施，有必要加深对骨盆与安全带相互作用的理解。
在这项模拟研究中，通过有限元人体模型（FE-HBM）模拟（n = 369），分析了处于半刚性座椅设置且受到约束变化影响的50%百分位（身高和体重方面）男性倾斜乘客群体的滑下结果。为了考虑与骨盆形状相关的个体差异，使用统计形状模型预测大量随机的50%百分位男性骨盆。基于选定的测量值，从该集合中抽取一个子样本（n = 78）纳入分析。模拟的滑下结果和相应的乘客/约束参数用于生成预测滑下概率的元模型。
结果表明，50%百分位男性的随机变化在倾斜乘客的滑下结果方面可能与约束设计变化相当。显著的预测因素包括来自乘客的三个因素（骨盆角度、髂棘钩角度和H点前后位置）以及来自约束的三个因素（扣环角度(^1)、座椅摩擦力和座椅座面角度）。不显著的预测因素包括乘客软组织厚度和脂肪硬度、肩带负载极限力以及单根安全带预紧的包含/排除。
总之，本研究表明，如果不统一目标乘客的解剖结构/姿势，使用不同版本的50%百分位男性FE-HBM的未来车辆安全评级在滑下结果方面可能会有所不同。此外，基于在半刚性座椅设置中的响应，本研究还表明，为了对倾斜乘客实现可靠的防滑下保护，当前对扣环角度的法律要求可能需要转向更垂直的角度。
(^1)原文中“buckle angle”未明确是指哪种扣环角度，此处保留英文以便准确传达原文信息。
