Research On Kinematics Analysis And Experimental Of Pneumatic Soft Grasping Robot

Unlike the traditional rigid robot,which is connected by connecting rods and joints,soft robot is a kind of robot with infinite degrees of freedom made of flexible materials.It has super environmental adaptability and flexibility,as well as good human-computer interaction ability.It has a broad application prospect in field exploration,military reconnaissance,medical rehabilitation,object grabbing and so on.Grabbing objects has been an important application direction of robots.With the great development of industrial automation,the grasping of items has become more and more diversified.The traditional rigid gripper can no longer meet the requirements of grasping fragile and irregular items,so the study of soft gripper is very important.In this dissertation,after analyzing the driving mode of soft robot,a pneumatic soft manipulator is designed.The feasibility of soft manipulator design is proved by theoretical analysis and finite element simulation.Using the combination of top fixture and soft manipulator,a pneumatic adjustable grasping diameter soft gripper is designed.Finally,the feasibility and the superiority of soft manipulator is verified by experiments.The main contents and contributions are as follows:Firstly,by analyzing the driving mode and material selection of the designed soft manipulator,we choose the pneumatic way to use silica gel to make the manipulator.Then,the principle of pneumatic action is analyzed.The stiffness of different flexible materials is different.Through the combination of flexible materials of different materials,the movement direction of the soft actuator can be controlled after gas is injected.The strain layer and constraint layer of the soft manipulator are designed,and a fixture that can change the grasping diameter is designed.The simulation diagram of the soft gripper is drawn with Solid Works software.Secondly,the soft manipulator is modeled by piecewise constant curvature method.Modeling constraints are specified.On this basis,the relationship between the end-center pose and joint variables and the relationship between joint variables and euler Angle are analyzed.Then the air cavity deformation model is established and the air cavity on the soft manipulator is modeled and analyzed.The theoretical relationship between bending Angle and gas pressure is obtained.Finally,ABAQUS software is used for finite element analysis of the soft manipulator,and the wall thickness of the soft manipulator and the spacing between the air cavities are optimized.The relationship between the bending Angle and gas pressure of the soft actuator under theoretical calculation and finite element simulation is compared,and the correctness of the theoretical modeling is verified.Then,the selection of materials and equipment for making pneumatic soft gripper is addressed.By using 3D printing technology and silica gel irrigation technology,we make the strain layer and constraint layer of soft manipulator,and the top fixture of soft gripper,and assemble the three parts to complete the preparation of soft gripper.The pneumatic control system is designed to prepare for grasping experiment.Finally,the pneumatic control system is designed and the test platform is built.The relationship between bending Angle and pressure of soft manipulator is verified.The adaptability of grasping diameter,grasping quality and grasping different articles are tested,and the superiority of grasping performance is verified.