Department of Robotics and Mechatronics, Korea Institute of Machinery and Materials, Daejeon 34103, Republic of Korea. School of Mechanical Engineering, Chungnam National University, Daejeon 34134, Republic of Korea. Both authors contributed equally to this work.
Bioinspir Biomim. 2019 Nov 6;15(1):016001. doi: 10.1088/1748-3190/ab46f7.
This paper presents a human-mimetic manipulator capable of shock absorption by using dislocation at the soft joint. A one degree-of-freedom (DOF) soft robot joint was developed based on the human elbow-joint structure, especially mimicking the humeroulnar joint in the elbow. Each component of the soft joint is combined by an elastic ligament, which is made up of elastic rubber and is attached to the pivot joint pin positioned at a predetermined place according to a specially designed pin guide. As an external impact is applied to the joint, the elastic ligament is elongated as the pivot joint pin is moved from the predetermined place. This state is defined as a dislocation, which is similar to the dislocation of a human joint when impacted. Dislocation in the proposed soft robot joint occurred when the external impact was larger than the predetermined threshold force. This threshold force can be predicted by the modulus of the elastic ligament and the shape of the pin guide, and the theoretical model was developed in this study. To evaluate the function of dislocation, dynamic and quasi-static impact tests were performed at the 1-DOF soft robot joint. Moreover, the human-mimetic manipulator is proposed based on the 2-DOF soft robot joint. This manipulator can realize four motions of a human arm using the pneumatic artificial muscles: flexion, extension, pronation and supination. Each artificial muscle and bone structure were similar to the human arm structure, and thus the configuration of each bone structure of the manipulator for each motion is similar to the configurations of a human skeletal structure. This manipulator was also capable of dislocation to absorb the external impact. The developed human-mimetic manipulator with a soft joint is expected to be applied to a naturally safe humanoid robot that works with humans in the same space.
本文提出了一种利用软关节的位错来实现减震的类人操作臂。基于人体肘关节结构，特别是模仿肘部的肱尺关节，开发了一种单自由度（DOF）软机器人关节。软关节的每个部件都是通过弹性韧带组合而成的，弹性韧带由弹性橡胶制成，并根据专门设计的销钉导向器附着在预定位置的枢轴销钉上。当关节受到外部冲击时，弹性韧带会随着枢轴销钉从预定位置移动而伸长。这种状态定义为位错，类似于人体关节受到冲击时的位错。当外部冲击大于预定的阈值力时，所提出的软机器人关节会发生位错。这个阈值力可以通过弹性韧带的模量和销钉导向器的形状来预测，本研究还开发了理论模型。为了评估位错的功能，在 1-DOF 软机器人关节上进行了动态和准静态冲击测试。此外，还基于 2-DOF 软机器人关节提出了类人操作臂。该操作臂可以使用气动人工肌肉实现人类手臂的四个运动：弯曲、伸展、内旋和外旋。每个人工肌肉和骨骼结构都类似于人类手臂结构，因此操作臂的每个骨骼结构的配置类似于人类骨骼结构的配置。该操作臂还能够发生位错以吸收外部冲击。这种具有软关节的类人操作臂有望应用于在同一空间与人类一起工作的自然安全的人形机器人。
