Variable stiffness and recruitment using nylon actuators arranged in a pennate configuration
Variable stiffness and recruitment using nylon actuators arranged in a pennate configuration
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使用羽状配置的尼龙致动器实现可变刚度和募集
DOI：
10.1117/12.2086799
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发表时间：
2015
影响因子：
9.4
通讯作者：
J. Madden
中科院分区：
文献类型：
--
作者：
Soheil Kianzad;Milind S. Pandit;Johnathan D. Lewis;Alexander R. Berlingeri;Karl J. Haebler;J. Madden
在肌肉中，可变阻抗和根据需要招募纤维的能力有助于实现行走和捕捉等动作。提出了一种新的仿生尼龙执行器结构，它在结构上模仿了人类的羽状肌，具有改变刚度的能力，并能够通过吸收额外的纤维来增加力。该驱动器由16根镀银尼龙缠绕纤维组成，以20°的角度附着在中心腱上。每个尼龙线圈在固定长度时产生20兆帕的应力，在固定负载时产生近20%的应变。使用晶体管分别开启和关闭光纤，这样每个元件都可以被招募，硬度也会发生变化。输入功率的大小由脉宽调制(PWM)技术控制。观察到，在25N的负载下，羽状结构的弹性常数从被动状态的503N/m和共振频率1.4 Hz变化到1480N/m和共振频率3.1 Hz的主动状态。刚度可以按9倍的系数变化。
In muscle variable impedance and ability to recruit fibers as needed helps enable actions such as walking and catching. A new biomimetic structure of nylon actuator is presented that imitates the human pennate muscle in structure, ability to vary stiffness and the ability to increase force by recruiting additional fibers. The actuator consists of 16 silver coated nylon coiled fibers attached to a central tendon at an angle of 20°. Each nylon coil produces 20 MPa of stress at constant length and nearly 20% strain at fixed load. Fibers are individually switched ON and OFF using transistors so that each element can be recruited, and the stiffness varied. The amount of input power is controlled with pulse width modulation (PWM) techniques. It is observed that the spring constant of the pennate structure varies from that of its passive state, 503 N/m and a resonance frequency of 1.4 Hz, to 1480 N/m with resonance frequency of 3.1 Hz in the active state where all the fibers are switched on under a 25 N load. Stiffness can be varied by a factor of 9.