Error Analysis Of Industrial Robots For Rapid Calibration

Because industrial robots are more and more widely used,there are higher requirements on the accuracy of industrial robots.Existing calibration technology has reached the level of certain maturity and high precision,but there are still some problems such as the error of calibration method and the incompleteness of the calibration model.This provides a certain space to enhance the calibration accuracy.Therefore,there is more significant meaning to do research on error analysis of industrial robot rapid calibration.In this paper,the error analysis of the robot calibration method was studied.With the influence of the flexible error on kinematics parameter,the error model was improved,thereby improved the absolute positioning accuracy of IRB120 industrial robot at two aspects.Firstly,we described the basic knowledge on kinematics of industrial robot in detail.Secondly,kinematics models are established respectively based on the classical D-H model and the modified D-H model(MDH model),and on the basis of this,some researches on derivation of forward kinematics equation for industrial robot and solving method of inverse kinematics problem have been done.In addition,zero calibration based on the point constraint and kinematics parameters calibration based on spherical constraint were described from three aspects including error model,constraint model and optimization model.All the above provided the basic theory preparation for the following research.In order to analyze the significance of kinematics parameter errors of each joint,the workpiece coordinate system was established on PSD platform.At the same time,based on the error analysis of industrial robot's static position and projection offset of the laser rays on the PSD sensitive surface,corresponding error cases were analyzed combined with the specific robot.A lot of time was spent on the analysis of the source of the industrial robot calibrated error especially the joint flexibility error.The main work included analyzing and establishing joint flexible error model.Combined with the specific robot,the flexible variation of the joint and the sensitivity of the PSD on joint flexible error were analyzed in this paper.The joint flexibility error model was integrated into the IRB120 kinematic calibration simulation system.The above work made a better preparation for the following research.Because the effect of joint flexibility error can not be ignored,the original error model of'zero calibration and kinematic parameters calibration on the basis of considering flexibility error were improved in this paper.The results of Matlab simulation show that imporved model is better than the original model.Finally,the calibration accuracy is improved from two aspects.