The Optimization Of Underactuated Multi-finger Manipulator Gripping Capacity And The Analysis Of Its Carrying Capacity

The human hand has the characteristics of more freedom,high flexibility,and large output.Until now,there is no robotic claw that can completely imitate the function of the human hand,in order to mimic the high flexibility,reliability,and wide applicability of the human hand as much as possible,the researchers developed a dexterous hand with high degrees of freedom.The under-actuated multi-finger manipulator claw is an end effector of an industrial robot.It has a unique mechanical structure and dexterous operating performance,making the planning of the target object very complicated.The gripping and grasping mode of the underactuated mechanism and the gripping stability,the stable reliability of the grip directly determines the success or failure of the design of the underactuated mechanism.Since the drive of the underactuated joint is non-independent with respect to the fully driven joint,the influence of its geometric parameters on the grip stability performance is unknown,and a complete multi-finger grab plan includes contact point position layout,contact model and more Finger positional shape planning,etc.It involves issues such as static balance,contact constraints,and motion constraints.In order to enable the under-actuated multi-finger manipulator to ensure the diversity of the grasping method and achieve stable grabbing,in this paper,according to the working principle and manufacturing process of a modular underactuated multi-finger manipulator,an underactuated multi-finger manipulator with variable finger configuration is designed and optimized.The main research contents are as follows:The structure of the three-dimensional model of the whole structure of the manipulator is optimized by using Creo software to determine its basic configuration.Furthermore,based on the modular design idea,structural function blocks such as finger modules and motor drive modules are designed.Design two finger mechanisms that enable multiple gripping methods,establish a robotic grab model and an object model,propose the structural parameters of the design to be optimized.According to the influence of multiple factors such as the grasping method and the quality of grabbing on the grasping stability of the robot,the forward kinematics and inverse kinematics model were established based on the D-H method.On this basis,a single finger is taken as an example to verify the accuracy of the kinematics positive and inverse solutions and the dynamic equations.Based on the structural characteristics of the underactuator and the requirements of the grab task,this paper analyzes the ADAMS simulation of different grasped objects according to the three different grab modes of the underactuator,obtain the contact force curve when the under-actuated hand is gripping stably,studies the motion characteristics of the finger mechanism,and verifies the underactuated The rationality of the overall structure of the hand.After the simulation environment is established,the goal is to minimize the stress on the fingers where the base knuckle pusher of the under-actuated finger and the central slider are connected in the three gripping modes,parameter optimization in ADAMS is to optimize the length and swing angle of the putter inside the base knuckle.And the mechanical data obtained by the ADAMS simulation is obtained after the optimal solution;the ANSYS is used to analyze the strength of the underactuated hand and two different finger mechanisms to verify the carrying capacity of underactuated hands and finger mechanisms.In the process of verifying the under-drive grasp grab stability,the nature of the finger greatly affects the grasp stability of the underactuated hand.The properties of a single finger of an underactuated manipulator are analyzed,and the influence of the position of the joint contact point and the contact force on the grasp stability is analyzed.A theoretical analysis method of the contact force and moment balance are proposed,and the influence of the grasp stability factor is probed.Thereafter,the design of the control system of the underactuated manipulator is performed,and a matching control program is prepared.The PC application interface can be used for gripping control,which can complete the grasping action of the robot itself and the indexing movement of the finger.Finally,the experimental platform for under-actuating multi-finger manipulator claws was built.The robot is mounted on the six degrees of freedom arm to verify the diversity,adaptability and stability of the gripper by grasping objects of different sizes,shapes and qualities.