Active muscles are crucial for maintaining postural stability when seated in a moving vehicle. Advanced active 3D non-linear full body models have been developed for impact and comfort simulation, including large numbers of individual muscle elements, and detailed non-linear models of the joint structures. While such models have an apparent potential to provide insight into postural stabilization, they are computationally demanding, making them less practical in particular for driving comfort where long time periods are to be studied. In vibration comfort and in general biomechanical research, linearized models are effectively used. This paper evaluates the effectiveness of simplified 3D full body human models to capture vibration comfort. An efficient seated human body model is developed and validated using experimental data. We evaluate the required complexity in terms of joints and degrees of freedom for the spine, and explore how well linear spring-damper models can approximate reflexive postural stabilization. Results indicate that linear stiffness and damping models can capture well the human response. However, the results are improved by adding proportional integral derivative (PID) controllers to maintain the defined initial body posture. The integrator is shown to be essential to prevent drift from the defined posture. The joint angular relative displacement is used as the input reference to each PID controller. With this model, a faster than real time solution is obtained when used with a simple seat model. The paper also discusses advantages and disadvantages of various models and provides insight into which models are more appropriate for motion comfort analysis. The results of this paper can provide valuable insights for designers, and researchers in the automotive and seating industries to improve the comfort and safety of seats and vehicles occupants.

翻译：主动肌肉对于在行驶车辆中保持坐姿稳定性至关重要。用于冲击和舒适性模拟的先进主动三维非线性全身模型已得到发展，这些模型包含大量单个肌肉元素以及关节结构的详细非线性模型。尽管这类模型在揭示姿势稳定机制方面具有显著潜力，但其计算需求高，尤其不适用于需研究长时间段的驾驶舒适性。在振动舒适性及一般生物力学研究中，线性化模型被有效应用。本文评估了简化三维全身人体模型在捕捉振动舒适性方面的有效性。我们基于实验数据开发并验证了一种高效坐姿人体模型。我们评估了脊柱所需的关节和自由度复杂度，并探讨了线性弹簧-阻尼模型近似反射性姿势稳定的能力。结果表明，线性刚度和阻尼模型能够较好地捕捉人体响应。然而，通过添加比例积分微分（PID）控制器来维持定义的初始身体姿势，结果得以改善。积分器被证明对于防止偏离定义姿势的漂移至关重要。关节角相对位移被用作每个PID控制器的输入参考。采用此模型，当与简单座椅模型结合使用时，可得到快于实时仿真的解。本文还讨论了各类模型的优缺点，并深入探讨了哪些模型更适合运动舒适性分析。本文的研究结果可为汽车及座椅行业的设计师和研究人员提供宝贵见解，以改进座椅和车辆乘员的舒适性与安全性。