The Design Of Robot Dexterous Hand With Three Fingers And Reasearch Of Defective Grasp Planning

As the end effector in humanoid robot system,dexterous robot hand has an important effect on the improving of operating efficiency and intelligence level in factory,and it also has played an important role in outer space operations,nuclear equipment maintenance,unknown environmental detection,underwater salvage operations and many other environments.Based on the latest electronic and control technologies and grasping operation theory,this paper studies the dexterous hand mechanical structure design,kinematics and dynamics analysis,control system design and multi-fingered hand defective grasp planning.The main work of this paper is as follows,Firstly,the overall structure of the dexterous hand is determined,and the driving and transmission mode middle finger and thumb are designed.The base joint of thumb achieves the pitching and lateral movement in both directions by using differential gear mechanism.The thumb position is optimized by maximizing the operable area,and the three-dimensional model is established in software.Then,the kinematic analysis of dexterous hand is carried out by using the robotics theory,the kinematic equations,Jacobian matrix of each finger are calculated and the working space of the fingertip is drawn.Taking the Lagrange method to deduce the dynamic equations of the index finger and thumb,and building the mechanical model of the thumb by Matlab/Simmechanics toolbox to complete the dynamic simulation analysis.Moreover,the overall structure of dexterous hand control system is designed by taking three-layer control structure and modularization idea,and the hardware design and actual circuit connection of single-finger controller are completed.A single-finger controller software system including single-finger control general flow,communication initialization,motion controller initialization,interrupt and joint position information acquisition program is designed.Finally,combined with the dexterous hand grasping kinematic and static equilibrium equations,the calculating process of dexterous grasping matrix and the definition of three grasping types are analyzed.Focus on the grasp planning of dexterous hand,the contact force is decomposed and computational method of passive balanced external force is deduced.Taking the maximum passive balanced external force as the evaluation indicator of defectivegrasp stability,the example is given to demonstrate its effectiveness.