Knuckles that buckle: compliant underactuated limbs with joint hysteresis enable minimalist terrestrial robots
Knuckles that buckle: compliant underactuated limbs with joint hysteresis enable minimalist terrestrial robots
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弯曲的指关节：具有关节滞后的顺应欠驱动肢体使极简地面机器人成为可能
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
N. Gravish
中科院分区：
文献类型：
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作者：
Mingsong Jiang;Rongzichen Song;N. Gravish
机器人肢体的欠驱动设计可以使这些系统被动地适应其关节配置响应于外力。被动适应和重构在需要复杂基质的操纵或运动的情况下是非常有益的。欠驱动系统的常见设计通常涉及致动多个旋转关节的单个腱，每个旋转关节具有抵抗弯曲的扭转弹性弹簧。然而，使用这些关节进行腿部运动的挑战在于肢体通常需要遵循循环轨迹，使得脚可以交替地参与站立和摆动阶段。这种轨迹对线性弹性欠驱动肢体提出了挑战。在本文中，我们提出了一种新的欠驱动肢体设计方法，其中包括滞后关节，改变他们的扭矩响应在加载和卸载。一个双关节欠驱动肢体与线性和滞后关节，从而可以调整，以创建各种循环轨迹。我们使用改进的基于层压的3D打印方法在柔性腿机器人内部制造这些关节，结果表明，通过被动顺应性和机械确定的关节序列，双腿极简机器人可以成功地通过不平坦衬底上的受限通道。
Underactuated designs of robot limbs can enable these systems to passively adapt their joint configuration in response to external forces. Passive adaptation and reconfiguration can be extremely beneficial in situations where manipulation or locomotion with complex substrates is required. A common design for underactuated systems often involves a single tendon that actuates multiple rotational joints, each with a torsional elastic spring resisting bending. However, a challenge of using those joints for legged locomotion is that limbs typically need to follow a cyclical trajectory so that feet can alternately be engaged in stance and swing phases. Such trajectories present challenges for linearly elastic underactuated limbs. In this paper, we present a new method of underactuated limb design which incorporates hysteretic joints that change their torque response during loading and unloading. A double-jointed underactuated limb with both linear and hysteretic joints can thus be tuned to create a variety of looped trajectories. We fabricate these joints inside a flexible legged robot using a modified laminate based 3D printing method, and the result shows that with passive compliance and a mechanically determined joint sequence, a 2-legged minimalist robot can successfully walk through a confined channel over uneven substrates.