Research On Machining Error Prediction And Compensation Of Robot Based On Stiffness

This research is based on the National Natural Science Foundation of China "Research on the mechanism of humanoid robot in the field of large complex workpiece remanufacturing",number:51065017.The application of industrial robots in machining is an important trend in the development of industrial robots.In this paper,when the MOTOMAN UP50 industrial robot is used for machining,the machining precision is low because of its weak rigidity,which can not meet the requirement of machining,the stiffness of MOTOMAN UP50 industrial robot is analyzed and its stiffness model is established,secondly,through the analysis of the end milling force,the cutting force model is established,based on the stiffness model and the end cutting force model,the error of the machining process is predicted,at the same time,the end error compensation model is established,and the joint compensation is used to improve the accuracy of the MOTOMAN UP50 industrial robot position control program.(1)Taking the MOTOMAN UP50 industrial robot as the research object,the kinematics equation is established by using the D-H method,and the forward and inverse kinematics of the robot is solved.(2)With the vector method and the differential transform method introduces the Jacobian matrix of 6 degree of freedom vertical joint robot,and using the differential transform method construct the Jacobian matrix,on this basis,the relationship between the force and torque of the robot and the force and torque of the connecting rod is solved.This paper analyzes the motion of the connecting rod,and establishes the relation formula of the connecting rod motion,and deduces the dynamic equation of the industrial robot by using the Lagrange method.(3)In the link rigid assumptions,ignore the link of inertia force and the influence of gravity,and the arm stiffness is known under the assumption that the analysis of joint stiffness and arm stiffness on the influence of end deformation,and thus establish the stiffness model of industrial robot,to explore a new modeling method for robot stiffness analysis.(4)The cutting force of MOTOMAN UP50 industrial robot is analyzed,and the cutting force model is established,then according to the stiffness model to establish a good robot,to predict the error produced by machining,and the amount of compensation by the joint joint angle to the position control of robot,so as to establish the robot error compensation model,provides a new method for compensating for error processing robot based on stiffness.(5)According to the established error compensation model,the feasibility and effectiveness of the compensation method is verified by the experiment of MOTOMAN UP50 industrial robot.