Design And Performance Analysis Of Embedded Skeletal Variable Posture Pneumatic Flexible Manipulator

Due to its flexibility,ductility and safety,flexible manipulator has attracted much attention in agricultural,industrial and medical fields,and has important theoretical research and practical application value.Traditional flexible manipulator is prone to deformation and has limitations when grasping objects.In this paper,aiming at the shortcomings of traditional flexible manipulator,a pneumatic flexible manipulator with embedded skeleton and variable posture is proposed.The main research contents are as follows:The structure,size and motion function of the human hand were analyzed,and the flexible finger was modeled by referring to the geometric size of the common male middle finger.The PLA embedded skeleton was designed to effectively limit the torsion and tensile deformation of the finger.According to the overall design scheme of the manipulator,the key components are designed to achieve the purpose of mutual conversion between different poses of the manipulator,so as to realize the spherical pinch,spherical grip and cylindrical grip three kinds of motion functions;The 3D printing consumables and silicone materials for making flexible fingers were studied.The stressstrain data of the materials were measured by uniaxial tensile test,and the Yeoh constitutive equation of E630 hyperelastic material was established.The required mold and endoskeleton were made using 3D printing technology,and the flexible parts were made by pouring silica gel to complete the production of the flexible manipulator.The mathematical model of flexural angle and flexural position of flexible fingers was established.The driving structure,endoskeletal structure and cross section shape of fingers were simulated by ABAQUS.The main and secondary effects of four groups of geometrical factors on the bending properties were obtained by orthogonal test.The control variable method was used to verify the change of bending angle and bending pose under different parameters,and finally the optimal parameter combination of fingers was obtained.A pneumatic control test platform was built to test the flexural performance of the flexible finger and verify the validity of the finite element model.The test compared the flexible fingers with or without endoskeletal end output force,and the results showed that the flexible fingers with embedded bones had better clamping performance.The diameter range of spherical kneading is 20～120mm and the maximum spherical kneading mass is about 260 g.Spherical grip diameter range of 60～120mm,the maximum mass of spherical grip about 300g;The diameter range of the cylindrical grip is 60～120mm,and the maximum mass of the cylindrical grip is about 340 g.Finally,the adaptability and stability of the flexible manipulator is verified by grasping a variety of objects of different sizes and qualities.