Does joint impedance improve dynamic leg simulations with explicit and implicit solvers?
Does joint impedance improve dynamic leg simulations with explicit and implicit solvers?
复制标题
关节阻抗是否可以通过显式和隐式求解器改善动态腿部模拟？
DOI：
10.1101/2023.02.09.527805
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Yakovenko,Sergiy
中科院分区：
文献类型：
--
作者：
Bahdasariants,Serhii;Barela,AnaMariaForti;Gritsenko,Valeriya;Bacca,Odair;Barela,JoséAngelo;Yakovenko,Sergiy
神经系统预测并执行由肌肉协调动作驱动的身体各部分的复杂运动。当中风或其他创伤性损伤扰乱神经处理时，受阻的行为不仅具有运动学属性，还具有需要解释的运动学属性。生物力学模型可以让医学专家观察到这些动态变量，并即时诊断出原本可能会被忽视的活动问题。然而，实时和特定于对象的动态计算需要对这些模拟进行优化。在这项研究中，我们探讨了本征粘弹性、数值积分方法的选择以及采样频率的降低对模拟精度和稳定性的影响。描述髋部、膝盖、脚踝和站立脚接触的17个旋转自由度(DOF)的两足动物模型使用了粘弹性元件，其静止长度位于DOF运动范围的中间。利用摆动相实验运动学进行了动力学仿真，对数值误差的累积进行了评估。评估了粘弹性、取样率和积分器类型之间的关系。这三个因素的最佳选择导致了随着模拟时间步长的增加，关节运动学(误差1%)和动力学(误差5%)的准确重建。值得注意的是，关节粘弹性减少了显式方法的积分误差，对隐式方法几乎没有额外的好处。所获得的见解有可能改进诊断工具，并准确地进行实时反馈模拟，用于神经肌肉疾病的功能恢复和对现代假肢解决方案的直观控制。
The nervous system predicts and executes complex motion of body segments actuated by the coordinated action of muscles. When a stroke or other traumatic injury disrupts neural processing, the impeded behavior has not only kinematic but also kinetic attributes that require interpretation. Biomechanical models could allow medical specialists to observe these dynamic variables and instantaneously diagnose mobility issues that may otherwise remain unnoticed. However, the real-time and subject-specific dynamic computations necessitate the optimization these simulations. In this study, we explored the effects of intrinsic viscoelasticity, choice of numerical integration method, and decrease in sampling frequency on the accuracy and stability of the simulation. The bipedal model with 17 rotational degrees of freedom (DOF)—describing hip, knee, ankle, and standing foot contact—was instrumented with viscoelastic elements with a resting length in the middle of the DOF range of motion. The accumulation of numerical errors was evaluated in dynamic simulations using swing-phase experimental kinematics. The relationship between viscoelasticity, sampling rates, and the integrator type was evaluated. The optimal selection of these three factors resulted in an accurate reconstruction of joint kinematics (err < 1%) and kinetics (err < 5%) with increased simulation time steps. Notably, joint viscoelasticity reduced the integration errors ofexplicit methodsand had minimal to no additional benefit forimplicit methods. Gained insights have the potential to improve diagnostic tools and accurize real-time feedback simulations used in the functional recovery of neuromuscular diseases and intuitive control of modern prosthetic solutions.