Method for calibrating geometrical parameter error of industrial robot based on two-step method

Abstract

The invention relates to a method for calibrating the geometrical parameter error of an industrial robot based on a two-step method. A calibration coordinate system is established and comprises a measuring coordinate system and a constraint coordinate system, an error model is established according to the interconversion relationship between a robot connecting rod coordinate system and the calibration coordinate system, and thus the preliminary calibration result of a conversion matrix between the robot connecting rod coordinate system and the calibration coordinate system is obtained; and then the preliminary calibration result is utilized to establish an error correction model including the robot connecting rod geometrical parameter error and the conversion matrix error between the robotconnecting rod coordinate system and the calibration coordinate system according to a differential perturbation method, the corrected robot geometrical parameter error is obtained, and the calibration method is simple and precise.

Description

Technical field [0001] The invention relates to an error calibration method, in particular to an industrial robot geometric parameter error calibration method based on a two-step method. Background technique [0002] With the expansion of the application field of industrial robots and the promotion of offline programming technology, the requirements for the absolute positioning accuracy of robots are getting higher and higher. The error sources that affect the robot's absolute positioning accuracy include geometric parameter errors and non-geometric parameter errors. The errors caused by geometric parameter errors account for more than 90% of the total error. Therefore, accurately identifying the robot's geometric parameter errors is the key to improving the absolute positioning accuracy. . Geometric parameter error is the deviation between the actual parameters of the robot and its nominal value due to manufacturing and assembly errors. The use of industrial robot calibration t...

AI Technical Summary

Problems solved by technology

In most studies, there are two methods to obtain the conversion relationship: (1) through high-precision machining and specially designed workpiece coupling to ensure the relative conversion relationship between the external device and the robot, which not only poses a challenge to the processing and design of the external device Higher requirements, and cannot be put into use quickly when the external device is worn out; (2) Calibrate the conversion relationship between the external device and the robot through a higher-precision measuring instrument. Inconvenient to use on site

Images