Multi-Joint Leg Moment Estimation During Walking Using Thigh or Shank Angles
Multi-Joint Leg Moment Estimation During Walking Using Thigh or Shank Angles
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DOI：
10.1109/tnsre.2022.3217680
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发表时间：
2022-10
影响因子：
4.9
通讯作者：
M. Eslamy;M. Rastgaar
中科院分区：
文献类型：
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作者：
M. Eslamy;M. Rastgaar
为了通过使用机器人假肢、矫形器或外骨骼来恢复类似人类的运动，一个主要的挑战是如何协调这些设备与生物肢体的运动。克服这一挑战的一种方法是首先确定下肢关节和肢体的运动学和动力学之间存在的关系。在这项工作中，我们旨在使用小腿或大腿角度连续估计矢状面踝关节，膝关节和髋关节的力矩。为此，在具有外源输入的非线性自回归模型中使用了神经网络和小波。这种方法避免了切换规则或中间参数的需要。为了评估评估器的性能，开发了四个案例研究。首先，大腿角度（输入）被用来估计臀部力矩（输出）。其次，利用大腿角度估计膝关节力矩。第三，使用大腿角度估计踝关节力矩，在第四个案例研究中，使用小腿角度估计踝关节力矩。使用三个不同的数据库，包括106名受试者以不同的步行速度评估评估质量。测试过程包括受试者之间和受试者内部的评估。从小腿角度估计踝关节力矩时，估计效果最好。当使用大腿角度以0.5 m/s的速度估计膝盖力矩时，观察到最弱的估计性能。在这种情况下，1.5 m/s的估计质量要好得多。髋部、膝关节和踝关节力矩的平均均方根误差分别为0.13 ~ 0.15、0.10 ~ 0.13和0.09 ~ 0.12 [Nm/kg]。髋关节、膝关节和踝关节力矩的平均绝对误差MAEs分别为0.10 ~ 0.11、0.07 ~ 0.10和0.06 ~ 0.08 [Nm/kg]。髋部和踝关节的平均相关系数分别为0.90 - 0.98和0.98 - 0.99。膝盖的值只有在高速时才具有可比性（1.5 m/s时为0.96），而在低速时则不太准确（0.5 m/s时为0.71）。总的来说，对于所有关节，虽然采用了一种输入来源（小腿或大腿角度），但估计精度与其他研究相当。
To reinstate human-like locomotion by using robotic prosthetics, orthotics or exoskeletons, a main challenge is how to coordinate the motion of these devices with that of the biological limbs. One approach to overcome this challenge is to identify firstly the relationships that exist between the kinematics and kinetics of the lower extremity joints and limbs. In this work we aimed to continuously estimate sagittal plane ankle, knee and hip moments using shank or thigh angles. For this purpose, neural network and wavelets were used in a nonlinear auto-regressive model with exogenous inputs. This approach circumvented the need for switching rules or intermediate parameters. To assess the performance of the estimator, four case studies were developed. First, thigh angles (inputs) were used to estimate hip moments (outputs). Second, thigh angles were used to estimate knee moments. Third, ankle moments were estimated using thigh angles, and in the fourth case study, ankle moments were estimated using shank angles. Three different databases involving 106 subjects at different walking speeds were used to evaluate estimation quality. The testing procedure involved both inter-subject and intra-subject evaluations. The best estimation performance was observed when ankle moments were estimated from shank angles. The weakest estimation performance was observed when knee moments were estimated using thigh angles at 0.5 m/s. For this case, the estimation quality was much better at 1.5 m/s. Average RMS errors were 0.13– 0.15, 0.10– 0.13, and 0.09– 0.12 [Nm/kg] for hip, knee and ankle moments, respectively. Average mean absolute errors MAEs were 0.10– 0.11, 0.07– 0.10, and 0.06– 0.08 [Nm/kg] for hip, knee and ankle moments, respectively. Average correlation coefficients were 0.90– 0.98 and 0.98– 0.99 for hip and ankle moment estimations. The value for knee was comparable only at high speed (0.96 for 1.5 m/s), while it was less accurate at slow speed (0.71 for 0.5 m/s). In general, for all of the joints, the estimation accuracy was comparable with that of other studies, although one source of input was employed (either shank or thigh angle).