Analysis Of Kinematics And Pose Error For 6-PTRT Parallel Robot

With the rapid development of artificial intelligence technology,the intelligentization of industrial robot has been paid more and more attention.Among them,they mainly focuses on the research of serial industrial robot and parallel industrial robot.Compared with serial robot,parallel robot has the advantages of large stiffness,high precision,strong bearing capacity and is easy to control,and is widely used in automobile manufacturing,aerospace and other areas.Among them,precision is one of the important performance indexes of parallel robot,which directly affects the performances of parallel robot and is also an important factor restricting its quality.Therefore,the analysis of the errors of parallel robot has important theoretical significance and practical engineering value for improving its accuracy.Taking 6-PTRT parallel robot as the research object,the kinematics and error-related problems of 6-PTRT parallel robot are analyzed in this paper,which provides a theoretical basis for trajectory planning,control and kinematical calibration of 6-PTRT parallel robot.The Kinematics analysis of robot includes forward kinematics analysis and reverse kinematics analysis,reverse kinematics of parallel robot is easy to be solved,while forward kinematics is difficult to be calculated.In this paper,the basical structure of 6-PTRT parallel robot is introduced,according to the structural characteristics and geometric relations of 6-PTRT parallel robot,the dynamic and static coordinate systems are established.The inverse solution model of the 6-PTRT parallel robot is established by the method of coordinate transformation,and the inverse solution equation of the 6-PTRT parallel robot is obtained.On the basis of solving the inverse equation of the position,according to the constraint relation and technical parameters of the 6-PTRT parallel robot,the mathematical model of the positive solution of the position is established.The problem of positive solution of position is transformed into an optimization problem of constrained multivariate nonlinear equations,which is solved by the swarm optimization algorithm with adaptive weight,and MATLAB software is used for simulation,and the correctness of the mathematical models of the inverse and positive kinematics solutions of 6-PTRT parallel robot are verified.This method is efficient,convergent and independent of the initial value,which provides a theoretical basis for the error analysis.In this paper,the pose error model of 6-PTRT parallel robot is firstly established,the closed-loop vector method of single branch chain is used to establish the error equation based on its input and output relationship,the control variable method is used to analyze the factors affecting the terminal pose error,and the correctness of the 6-PTRT parallel robot error model established by the single-branch closed-loop vector method is verified,which provides a theoretical basis for error analysis,error compensation and trajectory planning.According to the pose error model of 6-PTRT parallel robot,the mechanism error is converted into the drive rod error,the influence of the error parameters of each drive rod length on the output pose error is analyzed by using MATLAB software;The objective function of pose error correction of 6-PTRT parallel robot is established,and the adaptive weighted particle swarm optimization algorithm based on shrinkage factor is used to optimize the error parameters of each drive rod,modify the terminal pose,and improve the kinematics accuracy.Aiming at 6-PTRT parallel robot,this paper mainly analyzes the inverse position solution,positive position solution of kinematics,pose error and simulation,the correctness of the forward and inverse kinematics solution model of parallel robot and the factors affecting pose error are verified,which provides a theoretical basis for the dynamics,pose calibration and trajectory planning and control of 6-PTRT parallel robot.