Influence of Geometric Errors and Measuring Errors on Positioning Accuracy of an Industrial Robot This paper discusses the influence of geometric error parameters and measuring error parameters on the positioning accuracy of an industrial robot. Firstly, the kinematic model of a 6DOF industrial robot based on the modified DenavitHartenberg (DH) parameter method was established. Secondly, the influence of the geometric error parameters on the positioning accuracy of the robotxe2x80x99s endeffector is analyzed by simulation experiments in detail, including the link length errors, link twist errors, link offset errors and joint angle errors. And then the influence of measuring error parameters is also discussed. The results show that under individual effect of the linear errors, the length of positioning error of the robotxe2x80x99s endeffector is equal to the value of the corresponding error parameter. However, the angle errors have remarkable amplification effects on the accuracy of the robot. Moreover, it should be noted that the influence of measuring error parameters on the positioning accuracy of the robot is on the same order of magnitude as that of the geometric error parameters. Therefore, the measuring errors parameters should be taken into account during kinematic calibration.

Absolute Positioning Error Modeling and Compensation of a 6DOF Industrial Robot This paper presents an absolute positioning error modeling and compensation method considering measuring errors for a 6DOF industrial robot. Firstly, the error modeling of an ABB IRB 120 robot based on the modified DenavitHartenberg (DH) 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.