| With the multi-species,small quantities,personalized and customized products increasingly strong demand,five-axis machining technology with its unique processing advantages in the complex space curves and surfaces,will be more widely used.Based on the kinematic model of three typical five-axis serial machine tools,the causes of the nonlinear error of the five-axis linkage machine tool,the RTCP technology of the CNC system and the tilted plane machining technology of the five-axis positioning machine are studied.The kinematics model of the five-axis machine tool is the basis of the research on the five axis machining technology,the general transformation formula of kinematic chain from workpiece to tool of the five-axis serial NC machine tool is deduced by using the homogeneous coordinate transformation matrix,and the forward kinematics model of three typical machine tools is established.The nonlinear error caused by the two rotary axes is the key factor affecting the machining precision of the five-axis series machine tool.With kinematic decoupling method,qualitative analysis is carried out between CAM system post-processing module and actual machine from different perspectives of control point.Then,the process of compensating nonlinear errors by RTCP technique is studied.Aiming at the programming coordinate system of worktable and the workpiece coordinate system respectively,gives the nonlinear error compensation formula and compensation main body.Then the post-processing module of CAM system and the internal RTCP module of numerical control system are compared.Five-axis tilted plane processing is an effective means to improve the efficiency of five-axis machining.Five ways to definite feature coordinate system are designed,and then the inverse kinematics and the related intermediate quantities are studied,so a complete kinematic ring is established.The rotation basic angle algorithm of tool axis and the strategy of output angle judgment are given.The proposed RTCP algorithm is tested on the double-swing five-axis manipulator,experiments show that the RTCP technique realizes that the tool control point moves down to the tool center point.By using MATLAB and teaching software,the tilted plane machining algorithm is tested,and the simulation results show that the method can simplify the programming problem of spatial slope. |
