Research On Positioning Error Compensation Of 6-DOF Industrial Robot

In recent years,with the deepening of artificial intelligence research,robots have emerged in more and more fields as mechanical devices that can reflect intelligently,such as:aerospace,automobile manufacturing,3C,medical,etc.,which are safe,efficiency,and other aspects have the advantage of artificially incomparable.In the future,robots are developing toward high precision,high speed and intelligence.They are no longer the traditional form of recurring teaching.Off-line programming technology has gradually become a key factor for industrial robots to be widely used.Industrial robots currently on the market tend to have good repeatability,but absolute positioning accuracy is in the order of millimeters or even centimeters.The absolute positioning accuracy directly affects the effect of off-line programming,so the research on the accuracy of the end positioning has theoretical guiding significance and practical engineering application value.This paper takes EFORT industrial robot ER7L as the research obj ect.Firstly,it expounds the basic knowledge of robot kinematics.On this basis,it introduces the classic DH model,carries out kinematic analysis and uses robotics toolbox to verify the correctness of the model.In view of the shortcomings of the DH modeling method,the MDH model was finally adopted as the basis of kinematics research.In this paper,the research focuses on the geometric error,using the method of given kinematic parameter error to determine the sensitivity of length error,angle error and some minor errors in the kinematic parameters to the end positioning accuracy.By deducing the differential transformation relationship of adjacent joints,the error model is established by differential matrix method.In order to better compensate the error,the advantages and disadvantages of external hardware compensation and internal software compensation are compared.The easy-to-implement least squares method is chosen to identify the kinematic parameters of the robot.Aiming at the actual use situation of the industrial site,a compensation method based on the Pieper criterion is proposed,which greatly simplifies the identification parameters.In the experimental part of the article,the laser tracker,the robot body and the PC are used to build the hardware platform,and the RobotTest software is used as the software platform to compensate the error of an ER7L robot body.According to the industrial robot accuracy detection standard and method,the robot is compensated before and after.The accuracy of the end position is compared.The results show that the positioning accuracy is significantly improved,and the compensation effect is fully verified.