| As the end effector of industrial robots,mechanical grippers with different functions are applied in different environments.People have proposed various gripper design schemes to meet various task requirements.This article is inspired by traditional origami art and combines origami structure with mechanism,proposing a gripper that retains the origami movement while possessing the characteristics of traditional mechanism.By properly configuring the distribution of creases and optimizing the size of the panel,it has the ability to output large clamping and displacement within a small input angle range.The research content of this article is as follows:(1)Structure design of origami model.Using a folding structure with four creases and a single vertex as the minimum folding unit,combined with topology research methods,a series of foldable models are designed and summarized through horizontal and vertical concatenation stacking.Then,the rigid foldable verification method is used to verify the folding ability.(2)Origami gripper mechanism design and thickening.By analyzing the gripping motion process of human fingers and combining it with the origami structure,a gripper with origami motion characteristics is proposed;Calculate the degrees of freedom of the folding element and the origami gripper using the G-K formula and the Jiacobian matrix method,respectively.Considering the subsequent relevant analysis and application,the gripper will be thickened,and the adaptation environment of the thickened method will be analyzed in detail to determine the thickened plan.Compare the advantages and disadvantages of various driving modes and transmission modes,and select a design scheme that is suitable for the overall structure.(3)Kinematics and mechanics analysis of the origami gripper.Using the D-H method,obtain the angle change relationship between the folding unit and the combined structure of the folding unit;Kinematics analysis of zero thickness origami gripper and thick plate origami gripper is carried out,and the relationship between torsion angle,rotation angle,dihedral angle,output angle and output displacement is derived based on the angle change relationship;Use the closed-loop vector method to calculate the workspace,gripping speed,and acceleration of the left and right knuckles.Through the principle of virtual displacement,the mechanical balance equation is established,and the torque relationship and mechanical efficiency of each knuckle are obtained after solving.(4)Optimization design and simulation experiment of gripper.With mechanical efficiency,output angle and output displacement as performance indicators,through the relationship between structural design parameters and kinematics,the curve changes of panel size and input angle are analyzed to determine the optimization target parameters;Then define the output displacement and output angle as the optimization objective function and establish optimization constraints.After establishing an optimization mathematical model,genetic algorithm is used to solve and obtain the optimized relevant parameters.Establish a virtual prototype using optimized parameters,conduct simulation experiments on its motion process and mechanical analysis,and verify the motion model of the gripper. |
