Mechanism Design And Dynamic Performance Analysis Of A New Type Of Palletizing Robot

The current palletizing robot mainly adopt series structure,which has the advantage of large working space,but its shortcomings are that the drive motor and reducer are installed at each joint,which makes the robot inertia large,resulting in poor dynamic performance.In this paper,a new type of palletizing robot is proposed.By using several parallel controllable four-bar linkage mechanism,motor,reducer and other components are placed in the rack or the base,so that the height of the motor and reducer which originally installed in the serial-robot joints is significantly reduced,reducing the arm own load,expect to improve the joint hinge department of large inertia,poor machine stiffness and other issues,providing a design idea to enhance the dynamic performance of palletizing robots.In this paper,the mechanism design,kinematics and dynamics analysis of the robot is carried out,including kinematic characteristics analysis of the palletizing mechanism with motion pair clearance as well as modal simulation of robot.The method of DH solution and algebraic closed solution is used to analyze the forward and inverse kinematics of the robot.The speed of the robot is solved by the differential motion method,and the forward and inverse kinematic equations of the robot are simulated and verified.At the same time,the theoretical workspace of the robot is calculated by programming and the rationality of the design of the mechanism is verified.In the study of the robot dynamics,considering the influence of joint flexibility,the rigid and flexible coupling dynamic model of the robot is deduced and the simulation analysis is carried out.Moreover,the kinematic characteristics analysis and simulation of the simplified palletizing mechanism with motion pair clearance are carried out by using the two-state model of clearance.By comparing and analyzing the kinematic simulation results,the influence of motion pair clearance on the smoothness and accuracy of the mechanism is found.Finally,based on the modal simulation results of the robot,the natural frequency values,maximum deformation and vibration modes of the first six modes of the three typical pose of the robot are obtained.According to the vibration morphological characteristics of the robot in each mode,reference basis of forecasting and judging are provided to avoid large deformation of robot parts,machine resonance and other vibration problems.