多连杆刚柔机械手设计与手指减振分析

Design of multi-link rigid-flexible manipulator and analysis of finger vibration reduction

针对陶瓷易碎零件分拣过程中难以稳定抓取的问题,设计了一种能够有效稳定抓取的新型多连杆刚柔机械手。首先,以机械传动为基础,将刚性关节与柔性材料相结合,设计机械手的传动方式与柔顺关节的最优结构,并在三维软件上构建刚柔机械手的整体结构;其次,通过对机械手手指结构进行简化,采用拉格朗日理论和有限元离散方法,构建出具有尖端质量的手指多连杆刚柔耦合动力学模型;最后,求解出机械手手指在运动过程中的动力学方程。在此基础上,通过设计减振方案,对机械手手指结构做出优化和改进。仿真实验结果表明:在外激力为2 N的条件下,改进结构后的刚柔机械手手指其振动的幅度降低8 mm,且恢复稳定的时间缩短了4 s以上,在一定程度上提高了分拣和抓取过程中的抗冲击力,保证了对陶瓷易碎零件抓取过程的稳定性。

Aimed at the problem that it is difficult to grasp the fragile ceramic parts stably in the sorting process,a new multi-link rigid-flexible manipulator is designed,which can effectively and stably grasp them.Firstly,based on mechanical transmission,the rigid joint and flexible material were combined to design the transmission mode of the manipulator and the optimal structure of the flexible joint,and the overall structure of the manipulator was constructed on three-dimensional software.Secondly,by simplifying the structure of the manipulator finger,the rigid-flexible coupling dynamic model of finger multi-link with tip mass was constructed by using Lagrange theory and finite element discrete method,and the dynamic equation of the manipulator finger in the motion process was solved.On this basis,the finger structure of the manipulator was optimized and improved by designing the vibration reduction scheme.The simulation results show that the vibration amplitude of the fingers of the rigid-flexible manipulator with the improved structure is reduced by 8mm and the time to restore stability is shortened by more than 4s,which improves the impact resistance in the process of sorting and grasping to a certain extent and ensures the stability in the process of grasping ceramic fragile parts.