A Phase Variable Approach for Improved Rhythmic and Non-Rhythmic Control of a Powered Knee-Ankle Prosthesis
A Phase Variable Approach for Improved Rhythmic and Non-Rhythmic Control of a Powered Knee-Ankle Prosthesis
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DOI：
10.1109/access.2019.2933614
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发表时间：
2019-01-01
期刊：
影响因子：
3.9
通讯作者：
Gregg, Robert D.
中科院分区：
文献类型：
--
作者：
Rezazadeh, Siavash;Quintero, David;Gregg, Robert D.
尽管最近在控制节奏任务的多关节假体腿的控制方面取得了进展，例如步行，控制这些系统的非节律动作和一般现实世界动作仍然是一个空旷的问题。在本文中，我们开发了一个新的控制器，该控制器能够进行节奏（恒定）步行，速度和/或任务之间的过渡以及一些常见的自愿性腿部运动。我们引入了一个新的分段全体相变量，该变量通过有限的状态机构成了我们的控制器的基础。相变是通过测量大腿角来构建的，并且有限状态机中的过渡是通过感应脚接触和名义参考步态轨迹的属性来制定的。该控制器是通过膝盖骨骼假体实施的，并接受了经济截肢者的测试，他们成功地执行了各种节奏和非节奏的任务，包括缓慢而快速的步行，快速步行，快速启动，停下来，停下来，向后步行，步行，障碍和踢足球。与使用居家被动腿的使用相比，使用动力腿的使用导致节奏任务的截肢者补偿（包括拱顶和髋关节）的临床显着减少。此外，在非节律任务的绩效中，还观察到了很大的改善。预计所提出的方法将在统一框架中更好地理解对节奏和非节律动作的理解，这反过来又可以使对多关节假体的更可靠地控制更广泛的现实世界任务。
Although there has been recent progress in control of multi-joint prosthetic legs for rhythmic tasks such as walking, control of these systems for non-rhythmic motions and general real-world maneuvers is still an open problem. In this article, we develop a new controller that is capable of both rhythmic (constant-speed) walking, transitions between speeds and/or tasks, and some common volitional leg motions. We introduce a new piecewise holonomic phase variable, which, through a finite state machine, forms the basis of our controller. The phase variable is constructed by measuring the thigh angle, and the transitions in the finite state machine are formulated through sensing foot contact along with attributes of a nominal reference gait trajectory. The controller was implemented on a powered knee-ankle prosthesis and tested with a transfemoral amputee subject, who successfully performed a wide range of rhythmic and non-rhythmic tasks, including slow and fast walking, quick start and stop, backward walking, walking over obstacles, and kicking a soccer ball. Use of the powered leg resulted in clinically significant reductions in amputee compensations for rhythmic tasks (including vaulting and hip circumduction) when compared to use of the take-home passive leg. In addition, considerable improvements were also observed in the performance for non-rhythmic tasks. The proposed approach is expected to provide a better understanding of rhythmic and non-rhythmic motions in a unified framework, which in turn can lead to more reliable control of multi-joint prostheses for a wider range of real-world tasks.