| The progress of science and technology made robots more widely used in industry.6DOF industrial robots play an irreplaceable role in automobile welding,electrical and electronic,aerospace and other fields.However,the insufficient absolute positioning accuracy is the main problem in the application of 6 DOF industrial robot in the field of high-precision technology.In order to improve the absolute positioning accuracy of the 6 DOF industrial robot,the kinematics calibration theory and experiment of the GSK-RB08 6 DOF industrial robot are discussed.The structure of GSK-RB08 6 DOF industrial robot is analyzed,and its kinematics model established based on the modified kinematics modeling(MD-H)theory.Based on the theory,the forward and inverse kinematics solutions of RB08 robot are simulated,and the correctness of the kinematics model is verified.Considering the influence of geometric parameters and transmission errors of robots on absolute positioning accuracy,the error sources of absolute positioning errors are analyzed.The deceleration ratio coefficient and coupling coefficient are added into the kinematics model of 6-DOF industrial robot.The deceleration ratio coefficient,coupling coefficient and kinematics geometry parameters are used as error parameters to establish error models.The error parameters are identified by iterative Levenberg-Marquardt algorithm and verified by simulation.The experimental platform is built for experimental research.Firstly,according to kinematics model and error model,the software platform of 6 DOF industrial robot calibration with optional parameters is compiled;Secondly,the hardware experiment platform is built with laser tracker device,and the mathematical model of the point position and attitude characteristics is built with GB/T 12642-2001 as the final accuracy index of kinematics calibration.Data are collected and the correctness and advancement of the error model and calibration method are verified by comparing the calibration results with the deceleration ratio coefficient,coupling coefficient and the calibration results without the deceleration ratiocoefficient,coupling coefficient.Finally,the compensatable error parameters are compensated to the robot control system.According to the national standard GB/T 12642-2001,the point position and attitude performance parameters of RB08 robot are tested before and after calibration.The final result proves that the calibration method in this paper can effectively improve the absolute accuracy of 6 DOF industrial robot. |
PDF Full Text Request