Research On Elastodynamic Analysis And Error Compensation Of 3-pUU Parallel Robot

As a new development field,industrial robot plays an increasingly important role in the production process.As one of the representative industrial robots,Delta parallel robot is often used in automatic production lines such as food,medicine and consumer goods due to its simple structure,high running speed and low cost,which greatly improves the production efficiency of products.However,with the continuous expansion of the application range of parallel robots and the continuous improvement of the operation requirements of intelligent production lines,the work requirements of parallel robots are also continuously improved.In this paper,3-puu parallel robot is taken as the research object.Based on the comprehensive analysis of the motion error sources of 3-puu parallel robot,the rigid and flexible dynamics model is established,and the comprehensive error model is studied.On this basis,the compensation method for the error of the mechanism is proposed,which lays a foundation for further improving the motion accuracy of the 3-puu parallel robot.(1)Rigid-flexible dynamics modeling of 3-puu parallel robot.According to the structural shapes of the parallel manipulator's large and small arms,an appropriate spatial element model is selected.By solving the shape function,kinetic energy and deformation energy of the spatial beam element,the elastic dynamic equation of the spatial beam element in a definite system is obtained by combining with Lagrange equation.Use of space beam element of elastic dynamic mechanics equation established unit coordinate system,the dynamics equation of the big arm and forearm components through unit coordinate system and the system transformation relationship together with the big arm and forearm elasticity variable parameters,after coordinate transformation and assembly,branched chain flexibility under fixed coordinate system in system dynamics equation.By means of kinematic and dynamic constraints,the elastic dynamic equation of the system is obtained.Finally,the dynamic equation of rigid-flexible coupling is established.(2)Mechanism error model of 3-puu parallel robot.On the basis of considering the member flexibility in the previous chapter,this paper analyzes the causes of the position accuracy error of the parallel robot.In the machining and assembly of mechanical parts,the machining errors and assembly positioning errors also have an impact on the position accuracy of the parallel robot.The analytical method is used to establish the mapping relationship between the operating space at the end of the dynamic platform and the errors affecting the position accuracy,and then the comprehensive position error model of the3-puu robot is obtained.The coupling characteristics of the error source are analyzed,and the relation of the direction and position error with the change of the system coordinate system is explained.(3)Analysis of mechanism error compensation for 3-puu parallel robot.This paper mainly studies the compensation of mechanism error in trajectory planning.First put a continuous fixed trajectory as discretization points,which is converted to a number of points that could satisfy the requirement of precision,then the structure error caused by the position precision effect into the error of the driven member,finally USES the particle swarm optimization(PSO),the trajectory of the driving component optimization,so as to realize the mechanism of error compensation,to correct drive component of the desired trajectory,in order to complete the end of the actuator position precision is improved.(4)3-puu parallel robot virtual prototype and simulation experiment.Based on the virtual prototype of 3-puu parallel robot,the simulation experiment is carried out,including the inverse solution model,velocity model and acceleration model analysis of the kinematics of the driving slider.The influence of the error source on the end precision of the main mechanism was parameterized by Adams.In order to verify the influence of elastic construction on the end precision,the method of combining numerical solution analysis with Adams-Ansys simulation was used for comparative verification.Finally,the compensation method of particle swarm optimization(pso)proposed above is explored through experiments.