Design And Analysis Of A Seven-degree-of-freedom Series-parallel Hybrid Feeding Manipulator

With the development of economy and society,the society has higher and higher requirements for productivity.Enterprises have gradually carried out research on automation and intelligence,and more and more robots have been used in the production line,with high efficiency and low cost,gradually replacing the position of workers in the production line.In this paper,a seven-DOF series-parallel mixed handling manipulator is proposed for the automobile stamping production line.This manipulator can realize the automation of loading and unloading of stamping parts,and has the characteristics of fast movement speed and large working space.It is of great significance to improve production efficiency and liberate workers.The configuration of a seven-DOF series-parallel hybrid handling manipulator is designed.The manipulator is mainly composed of a bracket,a large arm(4-PRP_aR parallel mechanism),a small arm,and a pickup.The large arm is a parallel mechanism with three degrees of freedom and one rotation,and the small arm is a crank arm mechanism.The loading and unloading action is realized by the simultaneous movement of the big arm and the small arm.The simultaneous movement of the two arms and the speed superposition can improve the working rhythm of the manipulator,improve the production efficiency,and realize the automatic loading and unloading and workpiece detection of the stamping production line.Based on the G_F set theory,type synthesis is carried out and suitable parallel mechanism configurations are selected.A three-dimensional model of the mechanism is designed,and a forward and inverse solution model of the parallel mechanism is established.The mechanism is subjected to motion simulation to verify the forward and inverse solution models.Find the Jacobian matrix of the workspace and motion of the mechanism,analyze the influence curve of the mechanism parameters on the size of the workspace,analyze the speed and mechanical transmission performance of the large arm(4-PRP_aR parallel mechanism)based on the Jacobian matrix of motion,analyze the influence curve of the mechanism parameters on the speed and mechanical transmission performance,and based on the influence curve of the workspace size Select appropriate mechanism parameters based on the influence curve of speed transmission performance and mechanical transmission performance.In Cartesian space and joint space,respectively,the movement trajectories of the manipulator’s boom and jib are planned,the mechanism dynamics model is established,and the mechanism kinematics and dynamics simulation is carried out.The displacement,speed,acceleration,power,force and torque change curves of each driving joint are obtained through measurement.The curve is continuous and smooth,basically meeting the design requirements.According to the mechanism simulation analysis results,appropriate motors and ball screws are selected.