Virtual Constraint Control of a Powered Prosthetic Leg: From Simulation to Experiments with Transfemoral Amputees.
Virtual Constraint Control of a Powered Prosthetic Leg: From Simulation to Experiments with Transfemoral Amputees.
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DOI：
10.1109/tro.2014.2361937
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发表时间：
2014-12
期刊：
影响因子：
--
通讯作者：
Sensinger JW
中科院分区：
文献类型：
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作者：
Gregg RD;Lenzi T;Hargrove LJ;Sensinger JW
最近的动力（或机器人）假肢独立地控制不同的关节和步态周期的时间段，导致控制参数和切换规则可能难以由临床医生调整。这一挑战可能会得到解决，由最近的双足机器人，其中虚拟约束定义关节模式作为一个单调变量的函数，连续表示的步态周期阶段使用的统一控制模型。在第一次应用虚拟约束截肢运动，本文推导出精确和近似的控制律的部分反馈线性化，以执行虚拟约束的假肢。然后，我们将一个受人类启发的不变性属性（称为有效形状）编码到站立期间的虚拟约束中。在模拟了部分反馈线性化对临床有意义的条件的鲁棒性后，我们在动力经股腿上实验性地实施了这种控制策略。我们报告的结果，三个截肢受试者走在地上，并在可变的踏车节奏，证明了这种新的控制方法的临床可行性。
Recent powered (or robotic) prosthetic legs independently control different joints and time periods of the gait cycle, resulting in control parameters and switching rules that can be difficult to tune by clinicians. This challenge might be addressed by a unifying control model used by recent bipedal robots, in which virtual constraints define joint patterns as functions of a monotonic variable that continuously represents the gait cycle phase. In the first application of virtual constraints to amputee locomotion, this paper derives exact and approximate control laws for a partial feedback linearization to enforce virtual constraints on a prosthetic leg. We then encode a human-inspired invariance property called effective shape into virtual constraints for the stance period. After simulating the robustness of the partial feedback linearization to clinically meaningful conditions, we experimentally implement this control strategy on a powered transfemoral leg. We report the results of three amputee subjects walking overground and at variable cadences on a treadmill, demonstrating the clinical viability of this novel control approach.