Modeling the Kinematics of Human Locomotion Over Continuously Varying Speeds and Inclines.
Modeling the Kinematics of Human Locomotion Over Continuously Varying Speeds and Inclines.
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DOI：
10.1109/tnsre.2018.2879570
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发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
Gregg RD
中科院分区：
文献类型：
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作者：
Embry KR;Villarreal DJ;Macaluso RL;Gregg RD
动力膝关节和踝关节假肢可以执行有限数量的离散行走任务。这主要归功于它们的控制架构，该架构使用有限状态机在一组特定于任务的控制器中进行选择。支持连续任务的非开关控制器有望更好地促进规范的生物力学。本文介绍了一种预测模型，将步态运动学表示为步态周期百分比、速度和倾斜度的连续函数。基础模型由两部分组成：在步态周期内产生运动轨迹的基础函数，以及响应任务平滑改变基础函数权重的任务函数。来自 10 名身体健全的受试者以 27 种速度和倾斜度组合行走的运动数据为该数据驱动模型生成训练和验证数据。凸优化将模型准确地拟合到实验数据。自动模型降阶通过仅捕获步行任务引起的最重要的运动学变化来提高预测能力。对运动范围和冲击力的限制确保了用户的安全和舒适。该模型在任务上产生平滑的连续轨迹，这对于有限状态控制算法来说是不可能的。随机子采样验证表明基础建模比线性插值更准确地预测未经训练的运动学。
Powered knee and ankle prostheses can perform a limited number of discrete ambulation tasks. This is largely due to their control architecture, which uses a finite-state machine to select among a set of task-specific controllers. A non-switching controller that supports a continuum of tasks is expected to better facilitate normative biomechanics. This paper introduces a predictive model that represents gait kinematics as a continuous function of gait cycle percentage, speed, and incline. The basis model consists of two parts: basis functions that produce kinematic trajectories over the gait cycle, and task functions that smoothly alter the weight of basis functions in response to task. Kinematic data from ten able-bodied subjects walking at twenty-seven combinations of speed and incline generate training and validation data for this data-driven model. Convex optimization accurately fits the model to experimental data. Automated model order reduction improves predictive abilities by capturing only the most important kinematic changes due to walking tasks. Constraints on range of motion and jerk ensure the safety and comfort of the user. This model produces a smooth continuum of trajectories over task, an impossibility for finite-state control algorithms. Random sub-sampling validation indicates basis modeling predicts untrained kinematics more accurately than linear interpolation.