面向水下抓取作业的复合腔体仿生软体手设计

Design of a Bionic Soft Hand with Compound Cavity for Underwater Grasping

水下机械手在水生物采样、考古打捞等水下作业中起着关键作用,而现有水下机械手存在耦合安全性差、适应性弱及抓取不稳定等问题,使得作业效果并不理想。针对以上问题,本文开展了新型水下软体手的设计与研究。首先提出了具有密封管结构的复合腔体仿生软体驱动器,基于该驱动器设计出一种三指包络型水下软体手;硅胶材料的弹性和流体的可压缩性能够保证目标物的无损抓取,密封管结构可提高深水高压适应能力,保持腔和弯曲腔的复合结构及指纹、指甲的仿生结构提升了软体手耦合适应能力。利用基于Yeoh模型的有限元分析方法及注塑、3D打印等加工技术对软体手进行了结构优化和制作。设计了一套具有较高精度的水压驱动系统来提高软体手耦合稳定性。最后,针对影响机械手水下作业能力的重要因素,模拟相应实验场景对软体手进行了实验测试,实验结果显示软体手纵向抓取力达到26 N,驱动深度可达3000 m,较现有水下软体手均有较大提升;水下目标物抓取测试及与传统水下刚性手的对比实验证明了所提出软体手具有稳定的抓取性能和更好的适应性及安全性,适用于水下目标物的无损抓取作业。

Underwater manipulator plays a key role in underwater operations such as benthic organism sampling and archaeological salvage,but the existing underwater manipulator has some problems such as poor coupling safety,weak adaptability and unstable grasping,which make the operation effect not ideal.Aiming at the above problems,the design and research of a new underwater soft hand are carried out in this paper.Firstly,a bionic soft actuator with compound cavity and sealed tube structure is proposed.Based on the actuator,a three-finger enveloping underwater soft hand is designed.The elasticity of the silica gel material and the compressibility of the fluid can ensure the non-destructive grasping of the target.The sealed tube structure can improve the adaptability to high pressure in deep water.The composite structure of retaining cavity and bending cavity,as well as the bionic structure of fingerprint and fingernail,can improve the coupling adaptability of the soft hand.The soft hand is optimized and fabricated by using the finite element analysis method based on Yeoh model and the processing technologies of injection molding and 3D printing.A hydraulic drive system with high precision is designed to improve the coupling stability of the soft hand.Finally,the experimental tests on the proposed soft hand are performed for the important factors affecting the operating performance of the underwater manipulator by simulating the corresponding experimental scenes.The results show that the longitudinal grasping force of the soft hand can reach 26 N and the driving depth can reach 3000 m,which is higher than the existing underwater soft hands.The results of underwater target grasping test and comparison with the traditional rigid hand show that the soft hand has stable grasping performance,better adaptability and safety,and is suitable for non-destructive grasping of underwater objects.