Absolute Positioning Error Modeling and Compensation of a 6-DOF Industrial Robot

This paper presents an absolute positioning error modeling and compensation method considering measuring errors for a 6-DOF industrial robot. Firstly, the error modeling of an ABB IRB 120 robot based on the modified Denavit-Hartenberg (D-H) method was established, it took into account not only geometric errors but also measuring errors. And then the compensation method based on the joint angles was introduced. Secondly, the simulation experiments were adopted to verify the feasibility and effectiveness of the compensation method. Finally, the error compensation experiments were conducted, including the measurement, error identification, error compensation. The experimental results show that the accuracy can have a significant improvement of 73.94% after error compensation. Hence, the error modeling and compensation method presented in this study is sensible and effective, and could be used for the error compensation to improve absolute positioning accuracy of the industrial robots.