[论文解读] Systematic Evaluation of Hip Exoskeleton Assistance Parameters for Enhancing Gait Stability During Ground Slip Perturbations

Maria T. Tagliaferri, Inseung Kang|arXiv (Cornell University)|Jan 21, 2026

Prosthetics and Rehabilitation Robotics被引用 0

一句话总结

该研究在滑倒扰动中系统性改变髋部外骨骼的扭矩大小与持续时间，发现存在显著的交互作用，持续时间显著塑造稳定性结果，且实现WBAM（全身角动量）改进需要个性化参数。

ABSTRACT

Falls are the leading cause of injury related hospitalization and mortality among older adults. Consequently, mitigating age-related declines in gait stability and reducing fall risk during walking is a critical goal for assistive devices. Lower-limb exoskeletons have the potential to support users in maintaining stability during walking. However, most exoskeleton controllers are optimized to reduce the energetic cost of walking rather than to improve stability. While some studies report stability benefits with assistance, the effects of specific parameters, such as assistance magnitude and duration, remain unexplored. To address this gap, we systematically modulated the magnitude and duration of torque provided by a bilateral hip exoskeleton during slip perturbations in eight healthy adults, quantifying stability using whole-body angular momentum (WBAM). WBAM responses were governed by a significant interaction between assistance magnitude and duration, with duration determining whether exoskeleton assistance was stabilizing or destabilizing relative to not wearing the exoskeleton device. Compared to an existing energy-optimized controller, experimentally identified stability-optimal parameters reduced WBAM range by 25.7% on average. Notably, substantial inter-subject variability was observed in the parameter combinations that minimized WBAM during perturbations. We found that optimizing exoskeleton assistance for energetic outcomes alone is insufficient for improving reactive stability during gait perturbations. Stability-focused exoskeleton control should prioritize temporal assistance parameters and include user-specific personalization. This study represents an important step toward personalized, stability-focused exoskeleton control, with direct implications for improving stability and reducing fall risk in older adults.

研究动机与目标

• 促使在扰动中改进步态稳定性并降低跌倒风险，超越单纯的能量优化。
• 评估髋部外骨骼扭矩大小与持续时间如何影响 Ground Slip 时的全身角动量（WBAM）。
• 以稳定性为导向的参数相对于以能量为基础的基线进行基准比较。
• 量化个体特异的变异性与使用者在扰动中的稳定性感知。

提出的方法

• 开发了双侧髋部外骨骼，在矢状面可提供每髋最多18 Nm的扭矩。
• 在28个条件中应用五种持续时间和五种扭矩大小的时变梯形扭矩曲线。
• 将从16节标记无标记模型中测量WBAM作为主要稳定性指标，在扰动发生时进行测量。
• 使用径向基函数插值构建WBAM相对于扭矩大小与持续时间的连续二维表面，并对1000个表面进行自举以估计置信区间。
• 将表现最佳的参数集与无外骨骼以及以基线能量控制的控制器进行比较，使用被试内统计和线性混合效应模型。

Figure 1: Robotic hip exoskeleton designed to assist the user’s hip flexion and extension during locomotion. (A) Actuators located at each hip joint are controlled by an onboard microprocessor. Adjustable orthotic shells and pelvic strapping secure the device to the user. (B) A trapezoidal hip exten

实验结果

研究问题

• RQ1 外骨骼辅助的大小与持续时间如何相互作用影响滑倒扰动中的WBAM范围？
• RQ2 以能量优化为基础的基线控制器在稳定性方面是否有效，还是可以通过时序更关注且个性化的参数提升稳定性？
• RQ3 在不同被试中表现最好的参数区域是什么，以及在个体间的一致性如何？
• RQ4 主观稳定性评定（OPUS）与基于WBAM的客观稳定性量度之间的关系如何？

主要发现

• 滑倒时WBAM范围受辅助大小与持续时间之间显著交互作用的控制。
• 表现最佳的参数将WBAM范围分别比无外骨骼减少了27.4±9.8%，比基线控制器减少了25.7±11.4%。
• 个体之间的变异性显著；最优参数在不同个体间差异很大。
• 一般而言，延长辅助持续时间可以提高稳定性，但到达一定点后稳定性受持续时间的影响成为关键决定因素，可能具有稳定化与 destabilizing 的效应。
• 基线的以能量为导向的控制在减少WBAM方面效果较差，原因在于对屈曲相相互作用的时序把握不当。
• 插值分析在理论上给出在峰值生物力矩的15.9%和扰动长度的3.64×时的最优点位，自助法置信区间显示参数不确定性（大小量纲CI：10.1–21.6%；持续时间CI：3.48–3.72）。
• 被试报告在最佳参数下的感知稳定性更高（OPUS分数），相较于无辅助、无外骨骼和基线条件。

Figure 2: Experimental setup, protocol, and representative data. (A) Subjects experienced anteroposterior slip perturbations during treadmill walking while wearing the robotic exoskeleton. Anticipatory cues were minimized using noise-canceling headphones and visual-obscuring glasses. (B) The experim