Research On Trajectory Planning And Offline Programming Of Milling Robot

With the continuous development of machining and manufacturing,intelligence and automation have become the goal pursued by various industries.Industrial robots have been more and more widely used in milling because of their high flexibility and high intelligence.Milling robots often have complex trajectories and are not easy to program.Traditional linear and circular interpolation will lead to insufficient machining accuracy,and teaching programming will reduce machining efficiency.Therefore,studying the trajectory planning and off-line programming of milling robot has important practical significance to improve the machining accuracy and efficiency of the robot.In this thesis,Xinsong SR7 CL robot is taken as the research object to study its trajectory planning and offline programming.The research contents and results are as follows:Firstly,the kinematics model of SR7 CL milling robot is established by using the improved D-H method.The model parameters are determined according to the actual size,and the forward and inverse kinematics equations are derived.The kinematics equation is verified by MATLAB robot toolbox,and the Jacobian matrix of the robot is solved by vector method.Secondly,the NURBS curve theory is introduced.The NURBS surface is generated based on the NURBS spline curve as the surface of the machining.According to the CC path section line method and the row cutting method,the tool path and the tool path are determined.The ball end milling cutter is selected as the milling cutter.The residual height is introduced to calculate the row spacing of the trajectory,and the tool posture is preliminarily set.The milling scheme of the robot clamping the motorized spindle is designed,the milling coordinate system is established,and the working space is re-determined.Then,the trajectory position of the robot end is planned based on the S-type acceleration and deceleration control algorithm.The accuracy of the interpolation point is optimized based on the bow height error.The attitude control of the robot end is carried out according to the optimized attitude algorithm,and the optimal milling tool attitude is obtained.The trajectory planning of the robot is completed.The position of the workpiece is optimized by particle swarm optimization algorithm.Taking the sum of variances of each joint velocity curve as the measurement standard,the position of the workpiece with the most stable operation in robot milling is found.Finally,the motion simulation of the milling trajectory is carried out by PQArt.The simulation results show that the robot moves smoothly and does not interfere in the milling process.The post-processing interface in offline programming is designed by the GUI module in MATLAB software,and the automatic generation of robot control program is realized.The post-processing program of the trajectory is verified by building the SR7 CL robot milling experimental platform.