A Universal Ankle-Foot Prosthesis Emulator for Human Locomotion Experiments
A Universal Ankle-Foot Prosthesis Emulator for Human Locomotion Experiments
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DOI：
10.1115/1.4026225
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发表时间：
2014-03-01
影响因子：
1.7
通讯作者：
Collins, Steven H.
中科院分区：
文献类型：
--
作者：
Caputo, Joshua M.;Collins, Steven H.
机器人假肢有可能显着改善下肢截肢者的活动能力。然而，人类对与这些设备的机械相互作用表现出复杂的反应，并且计算模型还不能有意义地预测这种反应。因此，实验在开发中发挥着关键作用，但受到产品原型使用的限制，每个原型都需要多年的开发，并且专门用于狭窄的功能范围。在这里，我们描述了一个机器人踝足假肢系统，使人类受试者在实验中的广泛的动态行为的快速探索。该模拟器包括强大的非机载电机和控制硬件、灵活的Bowden线缆系绳和轻质仪表假肢，与现有平台相比，该模拟器具有低人体磨损质量（0.96 kg）和高机电性能。台架测试表明闭环扭矩带宽为17 Hz，峰值扭矩为175 Nm，峰值功率为1.0 kW。使用拟人摆“腿”进行的测试表明，系绳的干扰较低，髋关节周围的干扰小于1 Nm。这种低磨损质量、高带宽、高扭矩和无限制运动的组合使该平台具有非凡的通用性。为了证明对人体实验的适用性，我们进行了初步测试，其中单侧经胫骨截肢的受试者在跑步机上以1.25 ms（-1）的速度行走，同时假体以各种方式表现。这些测试揭示了低扭矩跟踪误差（RMS误差为2.8 Nm）和在宽范围内系统地改变功产生或吸收的能力（每步从-5 J到21 J）。这些结果支持使用机器人仿真器在早期阶段评估拟议的设备功能和人类-机器人交互的基本方面的科学研究。设计简单的替代末端效应器将使研究在其他关节或额外的自由度。
Robotic prostheses have the potential to significantly improve mobility for people with lower-limb amputation. Humans exhibit complex responses to mechanical interactions with these devices, however, and computational models are not yet able to predict such responses meaningfully. Experiments therefore play a critical role in development, but have been limited by the use of product-like prototypes, each requiring years of development and specialized for a narrow range of functions. Here we describe a robotic ankle-foot prosthesis system that enables rapid exploration of a wide range of dynamical behaviors in experiments with human subjects. This emulator comprises powerful off-board motor and control hardware, a flexible Bowden cable tether, and a lightweight instrumented prosthesis, resulting in a combination of low mass worn by the human (0.96 kg) and high mechatronic performance compared to prior platforms. Benchtop tests demonstrated closed-loop torque bandwidth of 17Hz, peak torque of 175 Nm, and peak power of 1.0 kW. Tests with an anthropomorphic pendulum "leg" demonstrated low interference from the tether, less than 1 Nm about the hip. This combination of low worn mass, high bandwidth, high torque, and unrestricted movement makes the platform exceptionally versatile. To demonstrate suitability for human experiments, we performed preliminary tests in which a subject with unilateral transtibial amputation walked on a treadmill at 1.25 ms(-1) while the prosthesis behaved in various ways. These tests revealed low torque tracking error (RMS error of 2.8 Nm) and the capacity to systematically vary work production or absorption across a broad range (from -5 to 21 J per step). These results support the use of robotic emulators during early stage assessment of proposed device functionalities and for scientific study of fundamental aspects of human-robot interaction. The design of simple, alternate end-effectors would enable studies at other joints or with additional degrees of freedom.