Positioning Accuracy Reliability Analysis And Error Compensation For Industrial Robot Based On Kriging Model

With the improvement of robotics and automation,industrial robots have become the core equipment in the field of intelligent manufacturing,and positioning accuracy is one of the key indexes to evaluate the performance of robots.The positioning error at the terminal of industrial robots,which caused by manufacturing errors,gear backlash and kinematic parameter error etc.,will affect the reliability of positioning accuracy.Compared with the repeated positioning accuracy,the absolute positioning accuracy of industrial robots is lower.Thus,improving the absolute positioning accuracy can promote the wide application of industrial robots.Based on Kriging model,an active learning reliability analysis method is proposed in this paper.After the example verification,the proposed reliability analysis method is applied to analyze the positioning accuracy reliability of industrial robots.Then,in order to improve the absolute positioning accuracy of industrial robots,a compensation method for positioning accuracy based on Kriging model is proposed,and the actual compensation effect of the proposed method is simulated and verified by experiments.The main research work of this paper is as follow:(1)The basic kinematics of industrial robots.Firstly,the classical D-H modeling method is introduced.Then,the kinematics model of a domestic 6-Do F polishing industrial robot was established by using D-H modeling method.Finally,based on the established kinematics model,the forward kinematics and reverse kinematics of the industrial robot are analyzed.(2)Hybrid reliability analysis for positioning accuracy of industrial robot.Due to the lacking of data information,it is difficult to obtain the accurate probability distribution types for some uncertain variables that affect the positioning accuracy of industrial robots.In view of this situation,the random and interval model is used to deal with this kind of reliability analysis problems.On this study,an active learning reliability analysis method based on Kriging model is proposed to efficiently and accurately analyze the positioning accuracy reliability of industrial robots.The computational efficiency and accuracy of the proposed method are verified by numerical examples,and then the proposed method is applied to the hybrid reliability analysis for positioning accuracy of industrial robots.(3)Compensation and experimental verification for positioning accuracy of industrial robot.In order to improve the absolute positioning accuracy of industrial robots,a compensation method for positioning accuracy based on Kriging model is proposed.Considering the influence of kinematic parameters error on the positioning accuracy,the positioning error model of industrial robot is established,and then the proposed accuracy compensation method is verified by simulation.In order to further verify the effectiveness of the proposed method,an experimental study is performed with HSR-JM612 industrial robot.The results show that the proposed accuracy compensation method can improve the absolute positioning accuracy of industrial robot by nearly 10 times,which prove that the proposed accuracy compensation method can effectively improve the absolute positioning accuracy of industrial robots.The research results provide theoretical support for the reliability analysis of positioning accuracy of industrial robots and the improvement of absolute positioning accuracy,which promotes the development of robot technology in some degree.