Design, Analysis, and Integration of a New Two-Degree-of-Freedom Articulated Multi-Link Robotic Tail Mechanism
Design, Analysis, and Integration of a New Two-Degree-of-Freedom Articulated Multi-Link Robotic Tail Mechanism
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DOI：
10.1115/1.4045842
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发表时间：
2020-04-01
影响因子：
2.6
通讯作者：
Ben-Tzvi, Pinhas
中科院分区：
文献类型：
--
作者：
Liu, Yujiong;Ben-Tzvi, Pinhas
根据对自然界的观察，尾巴被认为有助于动物实现高度敏捷的运动。传统的单连杆机器人尾巴可以很好地简化建模和实现目的。然而，这种方法不能解释自然界中表现出的复杂的尾部行为，在自然界中多环节结构更常见。与单连杆机械臂不同，铰接多连杆机械臂本质上属于串联机械臂家族，具有特殊的运动传动设计挑战。为了应对这一挑战，电缆驱动的超冗余设计成为最常用的方法。受电缆强度和弹性部件的限制，这种方法存在低频响应、产生的惯性载荷不足以及硬件脆弱等问题，这些都是机器人尾部设计的关键缺陷。为了解决这些结构缺陷，本文提出了一种由刚性连杆组成的多连杆机器人尾巴。新结构利用了传统的混合机构结构，但利用刚性机构来耦合第i杆和（i + 1）杆之间的运动，而不是使用电缆驱动。通过这样做，整个尾部成为一个刚性机构，每个部分实现准均匀的空间弯曲，并允许进行高动态运动。介绍了这种新型机器人尾巴的工作原理和详细设计。建立了刚性尾翼的运动学模型，并对其弯曲不均匀性进行了优化处理。基于这种特殊的优化设计，新机构的动力学模型得到了显著简化。为了验证该机构独特的机动性，集成了一个小尺寸的三段式样机。
Based on observations from nature, tails are believed to help animals achieve highly agile motions. Traditional single-link robotic tails serve as a good simplification for both modeling and implementation purposes. However, this approach cannot explain the complicated tail behaviors exhibited in nature where multi-link structures are more commonly observed. Unlike its single-link counterpart, articulated multi-link tails essentially belong to the serial manipulator family which possesses special motion transmission design challenges. To address this challenge, a cable-driven hyper-redundant design becomes the most used approach. Limited by cable strength and elastic components, this approach suffers from low-frequency response, inadequate generated inertial loading, and fragile hardware, which are all critical drawbacks for robotic tails design. To solve these structure-related shortcomings, a multi-link robotic tail made up of rigid links is proposed in this paper. The new structure takes advantage of the traditional hybrid mechanism architecture, but utilizes rigid mechanisms to couple the motions between the ith link and the (i + 1)th link rather than using cable actuation. By doing so, the overall tail becomes a rigid mechanism that achieves quasi-uniform spatial bending for each segment and allows performing highly dynamic motions. The mechanism and detailed design of this new robotic tail are presented. The kinematic model was developed and an optimization process was conducted to reduce the bending non-uniformity for the rigid tail. Based on this special optimization design, the dynamic model of the new mechanism is significantly simplified. A small-scale three-segment prototype was integrated to verify the proposed mechanism's unique mobility.