Piecewise and unified phase variables in the control of a powered prosthetic leg.
Piecewise and unified phase variables in the control of a powered prosthetic leg.
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DOI：
10.1109/icorr.2017.8009448
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发表时间：
2017-07
期刊：
影响因子：
--
通讯作者：
Gregg RD
中科院分区：
文献类型：
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作者：
Villarreal DJ;Quintero D;Gregg RD
已经提出了许多控制方法用于动力假肢，从在步态的离散相位之间切换的有限状态机到具有连续相位感的统一控制器。特别是，最近的工作表明，机械相位变量可以参数化整个步态周期，用于控制假肢在稳定的节奏运动。然而，统一的方法不提供对非节奏运动的自主控制，如向前和向后迈步。在本文中，我们提出了一种定相算法，使用截肢者的髋关节角度来控制有节奏和非节奏的运动，通过两种模式：1）分段（PW）功能，为用户提供自愿控制的立场和摆动分段的方式，和2）一个统一的功能，连续的截肢者用户在不同的步行速度的假肢的运动。这两个阶段变量的方法进行了比较，在实验中使用的动力膝踝关节假体膝上截肢者受试者。
Many control methods have been proposed for powered prosthetic legs, ranging from finite state machines that switch between discrete phases of gait to unified controllers that have a continuous sense of phase. In particular, recent work has shown that a mechanical phase variable can parameterize the entire gait cycle for controlling a prosthetic leg during steady rhythmic locomotion. However, the unified approach does not provide voluntary control over non-rhythmic motions like stepping forward and back. In this paper we present a phasing algorithm that uses the amputee’s hip angle to control both rhythmic and non-rhythmic motion through two modes: 1) a piecewise (PW) function that provides users voluntary control over stance and swing in a piecewise manner, and 2) a unified function that continuously synchronizes the motion of the prosthetic leg with the amputee user at different walking speeds. The two phase variable approaches are compared in experiments with a powered knee-ankle prosthesis used by an above-knee amputee subject.