Research On Positioning Accuracy And Error Compensation Of Joint Industrial Robot

With the concept of "Made in China 2025" proposed,the original industrial production methods are rapidly being replaced by automation and intelligence.As the main production tool of flexible automation,the performance indicators of joint industrial robot,especially the accuracy indicator,that directly determines the automation degree,the production efficiency and the product quality of production line.Accuracy is a hot topic in the field of robotics.In this paper,a new type of 4-DOF hybrid palletizing robot was used as the research object.Starting from kinematic error model,the positioning error caused by static error factors and dynamic error factors were analyzed respectively.And a positioning error compensation method was presented.All of the research are mainly reflected in the following aspects:In the establishment of kinematic error model.The MDH model for rotating joints was introduced in detail,and then the positive and inverse kinematics equations of the new hybrid palletizing robot were deduced by this model.At the same time,the "5-3-5" trajectory planning method was put forward,and the "5-3-5" trajectory planning program of the new hybrid palletizing robot was written in MATLAB.Finally,the kinematics simulation of "5-3-5" trajectory planning was completed in LMS Virtual.lab Motion,which verifies the correctness of the derivation of MDH model theory.These provides a theoretical basis for establishing robot kinematics precision model.In static error analysis.A probabilistic accuracy index was proposed to solve the problem of global positioning accuracy and error assessment of the robot.A robot positioning error model,which based on MDH model was established,and the MATLAB program for the global positioning accuracy analysis of robots,which based on probability accuracy method was designed.Finally,the probabilistic precision method was used in estimating the global positioning accuracy of the robot and the sensitivity analysis of the error source.These provided the theoretical basis for the selection of the optimal working point,and the design of the connecting rod accuracy and the assembly process of the robot.Also provided error data for error compensation.In dynamic error analysis.The model of rigid and flexible coupling for dynamic error analysis was established by using LMS Virtual.lab Motion software.And the simulation of the model was carried out by using control variable method.Then,the dynamic positioning error of the robot in the whole working space under different load conditions was obtained.Finally,according to the principle of independent error,the static and dynamic errors of the robot were synthetically integrated.And based on the method of spatial mesh,a method of iterative accuracy compensation of spatial mesh was proposed.And then various algorithms,which presented in the text and error databases were embedded in MATLAB GUI interface to development the interface of the new hybrid palletizing robot trajectory planning and positioning error compensation.The results of the example show that the positioning error compensation effect was good,which provides an effective method for improving the positioning accuracy of the robot in practice.