Preliminary Experiments with a Unified Controller for a Powered Knee-Ankle Prosthetic Leg Across Walking Speeds.
Preliminary Experiments with a Unified Controller for a Powered Knee-Ankle Prosthetic Leg Across Walking Speeds.
复制标题
使用统一控制器对不同步行速度的动力膝踝假肢进行初步实验。
DOI：
10.1109/iros.2016.7759798
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发表时间：
2016-10
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：
Quintero D;Villarreal DJ;Gregg RD
本文提出了一种新的控制策略，统一的动力膝踝假肢的整个步态周期，而不需要切换控制器之间的不同时期的步态实验验证。当前的控制方法将步态周期划分为多个连续的周期，每个周期具有独立的控制器，导致必须针对特定的行走速度来调整的许多患者特定的控制参数和切换规则。所提出的单个控制器是速度不变的，需要调整的控制参数的数量最少。一个单一的，周期性的虚拟约束，推导出确切的特征所需的驱动关节运动作为一个功能的机械相位变量跨步行周期。一个单一的传感器被用来计算一个相位变量有关的剩余大腿角的相平面，这是最近被证明是鲁棒地代表非稳态人体步态的相位。该相位变量允许假肢与人类用户自然同步，以实现直观的仿生行为。一个定制的动力膝踝关节假体的设计和建造，以实现控制策略，并验证其性能。以连续序列的多个步行速度（1至3英里/小时）使用基于单相的控制器进行人类受试者实验，证明其对用户预期速度的适应性。
This paper presents the experimental validation of a novel control strategy that unifies the entire gait cycle of a powered knee-ankle prosthetic leg without the need to switch between controllers for different periods of gait. Current control methods divide the gait cycle into several sequential periods each with independent controllers, resulting in many patient-specific control parameters and switching rules that must be tuned for a specific walking speed. The single controller presented is speed-invariant with a minimal number of control parameters to be tuned. A single, periodic virtual constraint is derived that exactly characterizes the desired actuated joint motion as a function of a mechanical phase variable across walking cycles. A single sensor was used to compute a phase variable related to the residual thigh angle’s phase plane, which was recently shown to robustly represent the phase of non-steady human gait. This phase variable allows the prosthesis to synchronize naturally with the human user for intuitive, biomimetic behavior. A custom powered knee-ankle prosthesis was designed and built to implement the control strategy and validate its performance. A human subject experiment was conducted across multiple walking speeds (1 to 3 miles/hour) in a continuous sequence with the single phase-based controller, demonstrating its adaptability to the user’s intended speed.