The Analysis And Experiment Research On The Chatter Stability Of Robotic Milling Processing

With the advent of the intelligent manufacturing era,the application of industrial robots is increasingly widespread.Industrial robots has successful application in handling,welding,spraying,and the processing of soft material,and industrial robots gradually replace machine tool to finish metal cutting machining to develop its the characteristics of high freedom degree and the strong flexible.According to the theory of industrial robotic milling chatter problem,the theory reasons of the chatter are analyzed and the robotic milling chatter model is constructed in this paper.Based on the model this paper has studied the effect of the cutter path and the workpiece clamping position on the stability of the robotic milling system by the experimental method.The cutter path and workpiece clamping position to reduce the chatter is optimized in the robotic milling processing and to improve the workpiece surface quality of robotic milling.The main work summary is listed as follows:In order to ensure the robot movement stability,robot kinematics analysis and simulation are considered.First of all,the connecting rod coordinate system of six freedom degrees robot is established using D-H representation method.Besides,the forward kinematics and inverse kinematics are solved.Based on the model of milling robot,the solution of forward kinematics and inverse kinematics are analyzed and the movement process is simulated.At the same time,in order to avoid the singular position in robotic milling process,the singular position is analyzed through solving the Jacobi matrix of milling robot in this paper.This paper identifies the each joint rigidity of milling robot through the static load experiment and calculates the robot end stiffness matrix combined the Jacobi matrix of milling robot.In view of the common posture in robotic milling process,the optimal area of stiffness value distribution is selected for the actual processing.At the same time,the dynamic cutting force in robotic milling system is studied and the chatter stability domain model in robotic milling system is established,which provides theoretical basis for the experimental study of robotic milling chatter.The robotic milling system is designed and the experiment platform of robotic milling machining is constructed in the paper to realize the real-time acquisition of the vibration signals and the force in end of robot.The corresponding modal parameters of robotic system milling under different work status are obtained through the modal analysis in robotic milling process,which provides the based data for the chatter stability researcher of robotic milling system.In the end,the influence factors on chatter stability of robotic milling are studied through experiments.The effect of cross coupling transfer function on chatter stability of robotic milling are analyzed theoretically,and two groups experiment is designed to analysis the effect of the cutter path and the workpiece clamping position on the stability of the robotic milling system.Besides,though the vibration test data of the robotic milling system,the chatter stability lobes diagram draw by the modal parameters,the surface roughness value of the robot milling machining and the comprehensive analysis of the two experiments results,the important conclusions to reduce the robot milling chatter effectively are obtained.