Designing And Testing Of Electrostatic Adsorption Type Flexible Pneumatic End-effector

As an important part of the robot,the end-effector is used to grasp,transfer or place,etc.,but the previous rigid or combine rigid and flexible end-effectors need to rely on the precise control system to grasp objects safely and losslessly.Moreover,the rigid end-effectors are poorly adaptable to objects,and different kinds of objects need to design different end-effectors.Therefore,the multi-grasping fully flexible end-effectors have become an inevitable trend of development.This paper proposes a novel electrostatic adsorption soft pneumatic end-effector,which combines gas drive and electrostatic adsorption to realize multi-mode grasping,has better adaptability and optimized grasping force,and simple structure and easy control,and can realize diversified grasping of objects of different shapes and sizes.In addition,the end-effector can complement the limitations of gas-driven and electrostatic adsorption,further improving the grasping efficiency and accuracy.Therefore,combined with the above requirements,the main research contents of this paper are as follows:(1)A symmetrical dual-finger and dual-air cavity integrated electrostatic adsorption soft pneumatic end-effector is designed.The the curvature structure of the root of the air cavity and the wall of the air cavity increases the safety and service life of the actuator body,and the actuator bending angle is analyzed based on the theoretical model of the air cavity of the finger root and the air cavity of the finger tip,the kinematic model of the end-effector is established by the D-H parameter method and the segmented constant curvature method.Finally,a theoretical model of electrostatic adsorption force was established based on the principle of electrostatic adsorption.Parameters of objective function and actual constraint conditions were optimized by using Python to obtain the optimal electrode parameters of electrostatic adsorption film.(2)Finite element simulation analysis of the width,height,wall thickness,spacing between air chambers and overall bending angle of the main chamber of the air-driven end-effector based on ABAQUS software to analyze its motion trend and obtain the most suitable chamber structure through simulation.Simulation of the electrode width,spacing,dielectric constant,insulation layer thickness and air gap of the electrostatic adsorption film based on COMSOL to analyze its adsorption force.The unit area adsorption force was analyzed by different electrode shapes established,and a better sine wave electrode structure with an amplitude of 2.5 was obtained by simulation.From the analysis results,it can be seen that the use of a variety of air cavity structures can change the bending angle of the actuator to achieve the gripping demand,and the special-shaped electrode can greatly increase the adsorption force of the electrostatic adsorption film.(3)The electrostatic adsorption type flexible pneumatic end-effector was prepared by using pouring method and screen printing method,and the experimental platform was constructed,finally the actuator was mounted on a mobile robotic arm to conduct experiments on the grasping performance of objects with different surfaces and weights as well as objects of different shapes.