Design And Study On Grasp Characteristics Of Negative Pressure Jamming Composite Flexible Gripper

With the rapid development of robot technology in China,robots are widely used in production and life.Traditional rigid grippers can meet some of the handling work in production,but they are difficult to achieve stable grasping actions when facing irregular or fragile items.Flexible grippers have relatively stronger grasping performance in the above fields,but due to their driving methods,they still have disadvantages such as low lifting ratio(grasping force/gripper mass),slow response speed,etc.,compared to rigid grippers.Therefore,it is of great significance to study flexible grippers that have high lifting ratio,high response speed and high versatility.To achieve stable grasping of irregular objects in complex scenarios,aiming at the problem that current research on mechanical grippers is less in complex life scenarios where the grasped objects are diverse,a negative pressure jamming composite flexible gripper combining jamming structure and negative pressure structure is proposed.Through finite element simulation,the structure of the wrapping part was optimized.The gripper was mechanically modeled and the grasping force was theoretically derived,and the factors affecting the grasping force were studied.Through experiments,the composition of the grasping force was analyzed and compared with the experimental results,verifying that the gripper can complete the task of grasping objects in complex scenarios.The main contents of this thesis are as follows:First,according to the design requirements and common grasping devices,three gripper schemes of pneumatic finger suction cup composite gripper,pneumatic finger jamming composite gripper and negative pressure jamming composite flexible gripper were proposed,and their advantages and disadvantages were analyzed and compared and selected negative pressure jamming composite flexible gripper as the optimal scheme.The overall scheme was designed in detail,and the flexible material for making the jamming airbag was selected.Through finite element simulation,the structure of the jamming airbag was analyzed,and the airbag structure was optimized.According to the design requirements,the suction cup and other rigid parts required for making the gripper were optimized in terms of structure.Second,the jamming airbag and jamming particles of the gripper were mechanically modeled,and the factors affecting the grasping force were analyzed,and the working principle of the jamming particles inside the airbag was studied,and its tensile stress and bending stress were studied.The grasping force was studied for spherical,cylindrical,prismatic and flat objects respectively,and the friction force,adsorption force and geometric locking force that make up the grasping force were theoretically derived respectively.Then,Moldflow software was used to analyze the injection molding of the jamming airbag,and the injection molding process parameters were optimized.The mold for jamming airbag was designed and manufactured.Finally,the gripper was assembled and installed,and the experimental gas circuit system was completed.Finally,a grasping force experimental platform and a grasping action experimental platform were built to verify the grasping performance of the gripper from multiple perspectives.Through filling effect experiment to determine the material and capacity of internal jamming particles,through grasping versatility experiment and grasping stability experiment to prove excellent grasping versatility of gripper through air pressure grasping force experiment different shapes and sizes object grasping force experiment different grasping conditions grasping force experiment proved that gripper has high lifting ratio.