Research And Implementation Of Smoothing Of Trajectory Technology For Five-axis CNC System

Five-axis NC machining technology is becoming mainstream trend in modern NCmachining because of its machining capacity for complex component parts. However,in five-axis NC machining, the traditional linear interpolation method in the processingof the part of free-form curves which largely change in curvature will result in cornertrace. In order to the realization of the high speed and high accuracy of five-axis CNC,this paper develops the research on smoothing of trajectory technology based on thegeneration instructions point principle of CAD/CAM.First of all, this paper introduces the present and future of modern NC machining,five-axis NC machining technology, the principle and research status of smoothing oftrajectory of NC system and the architecture of Lantian CNC system briefly.Secondly, according to the characteristics of Lantian CNC system, this paperproposes a finishing algorithm for instructions point for five-axis CNC. Based on thesmoothing of trajectory principle, this algorithm uses least square method in processingof instructions point and achieves interpolation computing on the smooth curve. Inorder to further improve the five-axis CNC machining efficiency, this paper alsoproposes smooth interpolation method for curve based on cubic polynomialdisplacement increment acceleration/deceleration control. This method will improvefive-axis CNC machining efficiency because it can improve the speed of tool betweenprogram segments and reduce the impact of the machine tool.Last, but not the least，based on the structure of motion controller of Lantian CNC,the method proposed by this paper is designed to simulative motion planning controller.The interpolation computing result of two actual cases outputted by simulative motionplanning controller is simulated to validate the efficiency of the method.