Control of a Powered Ankle-Foot Prosthesis Based on a Neuromuscular Model
Control of a Powered Ankle-Foot Prosthesis Based on a Neuromuscular Model
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DOI：
10.1109/tnsre.2009.2039620
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发表时间：
2010-04-01
影响因子：
4.9
通讯作者：
Herr, Hugh
中科院分区：
文献类型：
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作者：
Eilenberg, Michael F.;Geyer, Hartmut;Herr, Hugh
动力踝足假肢的控制方案依赖于固定的扭矩踝关节状态的关系，从测量的完整的人走在目标速度和已知的地形。虽然在其预期的步态速度和地形下有效，但这些控制器不允许适应环境干扰，例如速度瞬变和地形变化。在这里，我们提出了一种自适应肌肉反射控制器，基于仿真研究，利用踝跖屈肌包括山型肌肉与正力反馈反射。该模型的参数进行拟合，以匹配人踝关节的扭矩-角度曲线，该扭矩-角度曲线是从以1 m/s行走的体重和身高匹配的完整受试者的水平地面行走测量获得的。使用这一单一参数集，临床试验进行了与经胫骨截肢者在平地上行走，坡道上升，坡道下降的条件。在这些试验中，假肢踝关节工作的适应观察到地面坡度的变化，在一个完整的科目，没有明确的地形感知的困难。具体而言，假体提供的能量与地面坡度角直接相关。这项研究强调了神经肌肉控制器的重要性，以提高适应性的动力假肢设备在不同的地形表面。
Control schemes for powered ankle-foot prostheses rely upon fixed torque-ankle state relationships obtained from measurements of intact humans walking at target speeds and across known terrains. Although effective at their intended gait speed and terrain, these controllers do not allow for adaptation to environmental disturbances such as speed transients and terrain variation. Here we present an adaptive muscle-reflex controller, based on simulation studies, that utilizes an ankle plantar flexor comprising a Hill-type muscle with a positive force feedback reflex. The model's parameters were fitted to match the human ankle's torque-angle profile as obtained from level-ground walking measurements of a weight and height-matched intact subject walking at 1 m/s. Using this single parameter set, clinical trials were conducted with a transtibial amputee walking on level ground, ramp ascent, and ramp descent conditions. During these trials, an adaptation of prosthetic ankle work was observed in response to ground slope variation, in a manner comparable to intact subjects, without the difficulties of explicit terrain sensing. Specifically, the energy provided by the prosthesis was directly correlated to the ground slope angle. This study highlights the importance of neuromuscular controllers for enhancing the adaptiveness of powered prosthetic devices across varied terrain surfaces.