Villarreal Dario J, Gregg Robert D
Annu Int Conf IEEE Eng Med Biol Soc. 2014;2014:4017-21. doi: 10.1109/EMBC.2014.6944505.
Studies show that the human nervous system is able to parameterize gait cycle phase using sensory feedback. In the field of bipedal robots, the concept of a phase variable has been successfully used to mimic this behavior by parameterizing the gait cycle in a time-independent manner. This approach has been applied to control a powered transfemoral prosthetic leg, but the proposed phase variable was limited to the stance period of the prosthesis only. In order to achieve a more robust controller, we attempt to find a new phase variable that fully parameterizes the gait cycle of a prosthetic leg. The angle with respect to a global reference frame at the hip is able to monotonically parameterize both the stance and swing periods of the gait cycle. This survey looks at multiple phase variable candidates involving the hip angle with respect to a global reference frame across multiple tasks including level-ground walking, running, and stair negotiation. In particular, we propose a novel phase variable candidate that monotonically parameterizes the whole gait cycle across all tasks, and does so particularly well across level-ground walking. In addition to furthering the design of robust robotic prosthetic leg controllers, this survey could help neuroscientists and physicians study human locomotion across tasks from a time-independent perspective.
研究表明，人类神经系统能够利用感官反馈对步态周期阶段进行参数化。在双足机器人领域，相位变量的概念已成功用于通过以与时间无关的方式对步态周期进行参数化来模仿这种行为。这种方法已应用于控制动力型经股骨假肢，但所提出的相位变量仅限于假肢的站立期。为了实现更强大的控制器，我们试图找到一个能对假肢的步态周期进行完全参数化的新相位变量。相对于全局参考系的髋关节角度能够单调地对步态周期的站立期和摆动期进行参数化。本综述研究了多个相位变量候选方案，这些方案涉及在包括平地行走、跑步和上楼梯等多个任务中相对于全局参考系的髋关节角度。特别是，我们提出了一种新颖的相位变量候选方案，它能对所有任务中的整个步态周期进行单调参数化，并且在平地行走方面表现尤其出色。除了推进强大的机器人假肢腿控制器的设计外，本综述还可以帮助神经科学家和医生从与时间无关的角度研究人类在各种任务中的运动。
