Research On Error Detection And Modeling Of 6-DOF Robot In Milling

Compared with the traditional milling process,especially for complex artifacts,ordinary milling machine tool already cannot satisfy the requirement of efficient and accurate.In recent years,the use of industrial robots for processing become a research direction for many experts and scholars.Due to wide operation space,high flexibility and posture diversity of the robot.Its structure characteristics caused by poor rigidity which lead to some problems,such as the machining precision is not high,and affected by processing conditions.In addition,the study of robot processing mainly stay in the rapid prototyping aspect of non-metallic materials.The research of high precision milling robot is still in the basic phase.Therefore,in this paper,the error detection and compensation for milling aluminium alloy of robot is studied,which is based on machine vision measurement method that is put forward.This article main research content is as follows:The overall structure of the milling system scheme and error of each joint measurement scheme is firstly established according to the structural parameters of robot,milling and measurement requirements.This paper implements measurement of the joint angular motion error and the analysis of the location of the milling results,through dealing with the pictures the camera automatic acquired and using sobel operator for edge detection.Secondly,the robot kinematics equation is established based on D-H method,which takes TA-1400 robot as research objects.The coordinate system of robotic connecting rod between the transform is described,and forward and inverse solution of the robot also is solved.According to the kinematic parameters,the Jacobi matrix of the robot is calculated.According to the empirical formula,robot milling force is solved.The mapping relationship between robot end bearing and Joint forces is established through the establishment of the Newton-euler equation.Orthogonal experiment and the experimental data analysis is studied in the next stage.According to the robot structure parameters,robot error model is established,the relationship between different dosage of milling and the robot position error at the end of the milling is found out.The effect relationship between each joint deflection and total deflection at the end of the arm rod deflection is also the basis.Finally,the terminal error in practical milling is calculated based on robot error model.The amount of compensation at each joint is solved.Error compensation experiment was carried out on the milling processing which verify that the location of the robot end milling achieve optimization.