Abstract:
Industrial robots are getting more and more attention in the high-precision machining of complex parts of blade type due to their organizational flexibility and strong expandability, which puts forward higher requirements on the positioning accuracy of the robot end-actuator. In this paper, based on the six-degree-of-freedom articulated robot designed and developed independently, we conduct a research on the identification of geometric parameter errors and compensation methods, aiming to improve the positioning accuracy of the robot end-actuator. Firstly, the relationship model between the robot’s joint angles and end position coordinates is established based on the D-H method, and the position error model is established by considering the connecting rod length error, connecting rod bias error and joint angle error respectively. Secondly, the coordinate data measurement experiment is carried out based on the independently-designed special probe for the kinematic process, and the geometric parameter error term identification is carried out by using the Levenberg-Marquardt based on the experimental data. Finally, the geometric parameter error term identification and compensation method is carried out based on the independently-designed special probe error term identification. The identified results are compensated in the robot model and the effect of the compensation is experimentally verified, and the results show that the positioning accuracy after compensation is improved by more than 60% compared with the pre-compensation.