Dynamic Analysis And Multi-objective Structural Optimization Of 2RPS-PSP Parallel Robot

The parallel robots are developing towards high speed high precision,and intelligence with the advance in the plan of Made in China 2025.Parallel robots with fewer degrees of freedom are widely used due to their compact structure,low cost and relatively simple control.The 3-DOF 2RPS-PSP parallel robot was taken as the research object in this paper,whose dynamics model and the rigid-flexible coupling model were established,motion performance and structural parameters were analyzed and multi-objective optimization was performed,and the position and attitude of the moving platform were simulated.The main research contents of the thesis are:The dynamic model of 2RPS-PSP parallel robot was established.Aiming at the complexity of the dynamic model of the parallel mechanism and the difficulty of establishing its forward dynamic model,the dynamic model of the 2RPS-PSP parallel robot was established based on Udwadia-Kalaba theory and Lagrange method.The dynamic model of the robot was simulated and analyzed using the mechanical system dynamics simulation software Adams and the numerical calculation software MATLAB to verify the model.The rigid-flexible coupling dynamics simulation analysis of 2RPS-PSP parallel robot was carried out.Based on the finite element theory,the three branches meshes were refined using the pre-processing meshing software HyperMesh,and the modal neutral file was generated in the ANSYS using the command flow method.The file data transmission accuracy was verified by solving the modal frequency of the neutral file in ANSYS and Adams/Flex,The branch chain of the 2RPS-PSP parallel robot multi-rigid body model was converted into a flexible body in Adams,a rigid-flexible coupling dynamic model was established,and simulation analysis was carried out.In order to improve the kinematic performance of the 2RPS-PSP parallel robot,multi-objective structure optimization was carried out.Based on the spiral theory,combined with the Jacobian matrix,the global motion dexterity index,global mechanism binding force index and global motion/force index of the parallel robot were established to evaluate the robot kinematics,dynamics and statics performance.The robot multi-objective structure optimization model was constructed according to the above indexes,and the improved multi-objective particle swarm optimization algorithm was used to solve the optimization model.A PD control model was built to track the position and attitude the 2RPS-PSP parallel robot dynamic platform combining with Adams and MATLAB/Simulink software.The robot model was modified according to the optimization results.After setting the control input and output in Adams,a joint simulation model based on PD controller was built in MATLAB/Simulink.The simulation results show that the built model is reasonable and accurate.