Design And Research Of Robot Dexterous Hands Based On Parallel Finger Structure

With the development of science and technology,the application of robots in industrial production is also increasing,and robot technology has been rapidly developed.Traditional industrial robots generally consist of a tandem mechanical arm and an end effector,where the end effector is usually a simple clamping device,which is no longer capable of handling increasingly complex gripping tasks.The dexterous hand has the characteristics of multiple degrees of freedom and high dexterity,and has broad application prospects in the grasping operation.The finger structure of the traditional dexterous hand is generally a tandem structure,which uses artificial muscles,tendon rope drive and other under-driven driving methods,resulting in a low load capacity and precision of the dexterous hand,which cannot be applied to industrial production with large loads.Aiming at the above problems,this paper combines the characteristics of parallel mechanism with high rigidity,large load-bearing capacity and small accumulated error,and designs a robot dexterous hand with parallel finger structure.Firstly,studying on motor function of human hand,we can get the freedom of the finger and the range of motion.Based on the freedom of the finger,a type of parallel mechanism is proposed by the type synthesis method of Lie group theory,the finger mechanism is determined after performance optimization,and a robot dexterous hand based on parallel fingers is designed.Secondly,the kinematics and finger performance of the dexterous hand and finger mechanism are analyzed.The forward and inverse solutions of the finger mechanism and the Jacobian matrix of the finger mechanism are studied.The working space,singularity,dexterity and force transmission of the finger mechanism are analyzed.And optimize the structural parameters of the finger mechanism.Next,the two modes of precision operation and power grasping are studied.In precision operating mode,the in-hand degree of the dexterous hand,the relationship between the posture of the object and the position of the finger joint,and the optimal solution of the contact force between the finger and the object are analyzed.In power grasping mode,the carrying capacity of dexterous hands is analyzed.Then,finite element static simulation and motion simulation analysis are performed on the dexterous hand to verify the structural strength and motion function of the dexterous hand.Finally,a parallel dexterous hand prototype is manufactured,and related operation experiments are carried out.Theoretical analysis and experimental results show that the parallel dexterous hand designed in this paper can achieve in-hand precision operation and power grasping and has certain advantages in dexterity and carrying capacity.The dexterous hand has good self-adaptability and can switch different gripping modes for objects of different shapes,which can basically meet the requirements of flexible gripping operations in industrial production.