Kinematics calibration research based on the positioning error of the 6-DOF industrial robot

The forward kinematics model is deduced by combining the D-H method and MD-H method. The Jacobian matrix is deduced by total differential calculation. Thus, a kinematics calibration error model is established in this paper. The positioning accuracy of a SIASUN SR165C industrial robot is improved by using a 24-parameter calibration model. The error model takes into account all geometric parameters. The least square method is used to find the 24 error parameters. The simulation of the robot's positioning accuracy is performed with 100 points throughout the complete robot's joint space. After calibrating, the maximum positioning error on the end-effector is reduced from 0.541499 mm to 0.070459 mm, the average positioning error on the end-effector is reduced from 0.225000mm to 0.041075 mm, and the fluctuation of the error decreases.

I. Introduction

Industrial robots have been widely used in transporting, welding, painting, assembling, processing, etc. In many application fields, accuracy plays a significant role, the requirement for the positioning and orientation accuracy of the industrial robots is pressing. Industrial robot is a complex open-loop system, and the accuracy of the robot is easily affected by many factors, so its positioning and orientation accuracy is low [1]. It is important to improve the positioning accuracy of the industrial robot.