Motoman-UP6 Robot’s Trajectory Planning For Repair Control Of Bearing End Parts

Industrial production plays a very important role in the development of China’s national economy.Industrial production is inseparable from mechanical equipment,and there are a large number of bearing end parts in mechanical equipment that cause wear and tear due to long-term rotational friction and incorrect assembly.These minor damages will affect the accuracy and efficiency of the processed products.Due to these minor damages,directly replacing parts will cause a waste of resources,and the repair work of parts is particularly important in solving such problems.In the repair of the failed bearing end part model,most of the existing technologies are directly welding on the defective surface,which has the problems of roughness and inaccurate repair.In order to solve this kind of problem,this paper uses the Motoman-UP6 welding robot as a research tool.It will reconstruct the model of the damaged bearing end by increasing the longitudinal and lateral area of the damaged bearing end and the robot will reconstruct the bearing end repair path planning in two aspects.Research.The details are as follows:(1)Firstly,use the matrix to determine the robot’s position,posture and conversion representation;then establish the D-H coordinate coefficient model of the UP-6 robot,and perform the forward and inverse kinematics calculation and simulation verification of the UP-6 robot.According to the results of forward motion analysis,the Matlab program is designed by Monte Carlo method,and the three-dimensional working space of the robot’s end actuator is depicted in the coordinate system by the way of dot shooting to test the robot’s working ability.(2)Secondly,the model reconstruction of the damaged end of the failed bearing is proposed.By increasing its longitudinal and transverse areas,a more regular model of the end of the new bearing to be repaired is obtained.Solidworks is used to model the bearing end parts,and Matlab is used to extract the coordinates of STL grid format of the new model to be repaired,which provides coordinates calibration for the later repair trajectory planning.(3)Thirdly,the Cartesian space of the robot is planned,and the step lengthof the robot’s walking path is calculated by linear interpolation and circular interpolation respectively.The linear and circular motions of the robot in Cartesian coordinate system are planned.The inverse kinematics of the robot is used to solve the attitude angle of the end effector of each point,and the trajectory of the joint space of the robot is planned.The trajectory of middle path points is calculated and simulated by cubic polynomial interpolation and quintic polynomial interpolation respectively,and the advantages and disadvantages of the two methods are compared.(4)Finally,due to the strict requirements of trajectory accuracy when the robot carries out the specific tasks such as linear welding,arc welding,plane spraying,etc.,the transition trajectory is planned by using the method of cubic to quintic polynomial interpolation.When the number of intermediate positions and positions of the robot increases,the cumulative acceleration impact increases,resulting in the decrease of the stability and accuracy of the robot.Therefore,on the reconstruction model of increasing the longitudinal and transverse area of the damaged parts at the end of the failed bearing,a hybrid interpolation(3-5-3)repair trajectory optimization method is proposed,and simulation and experimental verification are carried out to improve the accuracy and stability of the robot repair work,and extend the service life of the bearing end parts by 3%.