Research On Online Force Error Measurement And Control Compensation Technology For Industrial Robot

High-end manufacturing reflects the comprehensive national strength of a country.At present,our country is developing a number of major projects,for example,High-speed technology,Large Aircraft Project,Nuclear project,Aerospace project.In order to improve the level of high-end manufacturing of our country,a strategic plan called “Made in China 2025” was presented by the State Council.And we have made breakthrough.All of these projects are need to be high-accuracy,complex structure and big size.Therefore,the workpiece needs to be high level.However,traditional methods can't meet its need.As we know,industrial robot has been more and more widely used in manufacturing fields because of its large workspace,flexible operation,small size and so on.It was an important composion of flexible system.While,the positioning accuracy,especially the absolute positioning accuracy of the robot is low.Therefore,it is limited in high-accuracy manufacturing fields.Hence,in this paper,a method to improve the absolute positioning accuracy of the robot is proposed.Besides,a robot online compensation system is built to compensate the robot error combined with algorithm.Finally,the robot absolute positioning accuracy is improved.The knowledge about a typical 6D serial robot is studied,including robot structure,robot operating mode,robot coordinate system and so on.Based on KUKA KR5 arc robot,the D-H model of this robot is also established,and the error of the robot model is also analyzed.Based on the model,the robot is calibrated and the absolute positioning accuracy is improved.The relationship between robot deformation and robot force is studied.And the robot stiffness model is measured by experiment.Besides,based on robot stiffness model,a robot compensation method is proposed.This method can measure the robot force and calculate the error by robot stiffness model.After that,the robot can compensate the error.The result shows that this method is effective.Based on method above,a robot force online compensation system is established.The compensation method is studied and a robot online compensation algorithm based on PID is proposed.The result shows that this system can improve the absolute positioning accuracy of the robot when it is weighted.