Stiffness Analysis of a Pneumatic Soft Manipulator Based on Bending Shape Prediction
Stiffness Analysis of a Pneumatic Soft Manipulator Based on Bending Shape Prediction
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基于弯曲形状预测的气动软体机械臂刚度分析
DOI：
10.1109/access.2020.2991423
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发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Lina Hao
中科院分区：
文献类型：
--
作者：
Ying Zhang;Wenlin Chen;Jie Chen;Qiang Cheng;Haikuan Zhang;Chaoqun Xiang;Lina Hao
柔性机械手由于其固有的顺应性和灵活性可以执行连续操作，从而能够在受限环境中进行安全的交互和平稳的运动。然而，高顺应性通常意味着低负载能力。柔性机械臂在保持刚度的同时具有适当的柔性是其应用的重要方面。因此，本文致力于一种变刚度机构的气动人工肌肉（PAM）驱动的软操作器。由于收缩和伸肌PAM的组合，操纵器能够独立于配置改变其刚度。基于PAM非线性和Cosserat理论耦合的非线性静力学模型，通过对柔性机械臂在不同加载和充气条件下的弯曲形状预测，定量分析了柔性机械臂的刚度特性。此外，进行实验测量，以进一步验证机械手设计的预期性能。实验和验证的理论分析结果表明，PAM的压力变化对机械手的形状和刚度有很大的影响，实现了大的弯曲空间和高输出力。变刚度设计明显提高了机械手在相同位置抵抗附加干扰的能力。
Soft manipulators can perform continuous operations due to their inherent compliance and dexterity, thus enabling safe interactions and smooth movements in confined environments. However, high compliance usually means low load capacity. It is important for a soft manipulator to possess proper flexibility while maintaining an acceptable stiffness to widen its applications. This paper has hence devoted efforts to a kind of variable stiffness mechanism for a soft manipulator actuated by pneumatic artificial muscles (PAMs). Due to the combination of contractile and extensor PAMs, the manipulator is able to vary its stiffness independently from the configuration. The stiffness characteristics of the soft manipulator are quantitatively analyzed by bending shape prediction under different loading and inflation conditions, and the prediction is built upon a nonlinear statics model coupled with PAM nonlinearity and the Cosserat theory. In addition, experimental measurements are conducted to further validate the expected performance of the manipulator design. The experimental and verified theoretical analysis results indicate that the manipulator shape and stiffness are greatly affected by the pressure variation of PAMs, realizing a large bending space with a high output force. The variable stiffness design obviously increases the manipulator’s ability to resist additional interference at the same position.