Research Of Kinematic Calibration And Derict Teaching Of Industrial Robot

Multi-degree of freedom serial mechanical arms are widely used in industrial production,medical surgery,logistics and other industries.By decades of development,Industrial robot technology has been basically mature.However,with the improvement of science and technology,the robot performance requirements of all industries have been more sophisticated.Improv the performance of the robot has been the urgent goal of the current robot manufacturers.This paper establishes the kinematic calibration method based on distance error in the first part.The laser tracker is used to measure the four-axis palletizing robot,and identify the nominal parameters error of the robot.After compensation,the absolute positioning accuracy of the robot will be improved.The kinematic model of the robot is established based on the D-H method,and the detailed forward and inverse kinematics derivation process is given.The kinematics model is simulated and verified by using the Matlab software to verify the correctness of the established kinematic model.Then the source of absolute error of the robot end-effector is analyzed,and the definition of distance error is introduced.The relationship between the distance error and the link parameter error is deduced,and the distance error model is established.Meanwhile,Building information collection platform in the process,with collection and storage of data as well as the establishment of error equation.Finally,the least squares method and the LM algorithm are used to solve the error equation.comparing the distance error before and after compensation,Levenberg-Marquard method achieve a better effect,which the accuracy of of absolute distance error improves 35%,meanwhile,the average value of distance error decreases from 2.20 mm to 0.27 mm.The latter part of the article based on the torque control achieves the CY3 A stamping discharge robot drag teaching.Compared with the traditional teaching methods,drag teaching has several advantages including simple,low demands on workers,high teaching efficiency,ability of achieving complex trajectory teaching,which is an important research direction of teaching technology.The direct teaching of the torque-free sensor has attracted attention because of the obvious cost advantage,and the robot's torque-free sensor is directly taught based on the principle of moment balance.In order to compensate the friction torque during teaching,a joint friction model was established.Using the tracking differentiator to obtain the accurate velocity signal,the friction curve of each joint was fitted according to the Coulomb-viscous friction model.For the heavier joint 1,the tracking differential is used to obtain its acceleration signal,and the inertia force is calculated and compensated.It is proved that the operation force of the joint is less than20 N after compensation.The kinematic calibration of the FR-120 A palletizing robot is carried out in this paper,and the CY3 A type blanking robot has been directly demonstrated,the theory in this paper can also be applied to other types of industrial robots,and the related results will be of guiding significance for improving the absolute localization accuracy of robots and realizing direct teaching.