Research On Pneumatic Gripper Structure And Visual-Touch Fusion Control For Intelligent Collaborative Robots

With the continuous development of society,the application domain of robots is constantly expanding.As an important medium for robots to interact with the external environment,grippers have always been one of the focuses of research.Compared with traditional rigid grippers,flexible grippers have higher flexibility,environmental adaptability and human-computer interaction,which can realize non-destructive grasping of fragile objects and are widely used in unstructured scenes of collaborative robots.However,in the unstructured environment,it is difficult to establish an accurate gripping model for flexible grippers,so it is necessary to use visual recognition information and tactile perception to carry out grasping operation research for unknown target objects.Taking a pneumatic flexible gripper as the research subject,this paper conducts research from the aspects of flexible material selection,material parameter determination,flexible finger structure design,bending deformation characteristic analysis,manufacturing process and construction of a complete set of visual-tactile fusion operating systems.The main research contents of the paper are as follows:(1)The characteristics of the flexible gripper driving mode and driving structure were analyzed and compared,and the flexible gripper driving mode and driving structure for the scene were selected according to the current application requirements and grabbing objects of the robot scene;The flexible material for making the gripper was selected,several constitutive models describing the mechanical properties of hyperelastic materials were analyzed,and the material parameters in the constitutive model were determined based on tensile experiments.(2)Based on the Abaqus finite element simulation platform,the influence of key structural parameters such as airbag shape,wall thickness,width,height,spacing,and number of airbags on the deformation characteristics of flexible fingers was analyzed and compared,and the relevant dimensional parameters of flexible fingers were finally determined.(3)Based on the principle of virtual work and the principle of torque balance,a mathematical model was established for the bending angle of the single airbag of a flexible finger and the whole finger,and the relationship between the bending angle of the pneumatic flexible finger and the input air pressure and finger structural parameters was analyzed.(4)Design the casting mold of flexible fingers,and use 3D printing technology to make the mold.Dragon Skin 30 silicone is used to cast the flexible fingers,and test the performance of the finished flexible fingers;and designed two grippers that can automatically adjust the gripping distance between flexible fingers.(5)The visual-touch fusion grasping operating system,which mainly included the construction of a flexible gripper tactile perception system,the construction of visual recognition system,and the design of an air path control system was built.Finally,on the Sawyer collaborative robot platform,the feasibility of the whole operating system is verified by the recognition and grasping experiment of unknown target objects.The research content of this paper provides feasible ideas and directions for robots to grasp unknown target objects,explores new ways to solve the safety and compatibility problems of robot end effectors,which is of great significance for promoting the practical application of flexible grippers.