Prediction And Visualization Simulation Of Machining Profile Error Of Triaxial Engraving And Milling Machine

At present,numerical control machining simulation software is mainly used for geometric simulation of machining instructions,which is used to predict the possible overrun,collision,overcut,undercut and other errors in the machining process and make them visible.In actual machining process,due to the dynamic characteristics of machine tool feed system will result in multi-axis linkage processing when the contour error in nc machining simulation software cannot be reflected,in order to predict the numerical control machine tool processing after the size and distribution of contour error,study the effect of multi-axis linkage contour error factors and laws,further study of the effective methods to reduce the contour error,in-depth study of multi-axis linkage contour error prediction and visualization method,has an important significance in theory research and engineering application value.Based on three axis CNC engraving and milling machine as the research object,the further study of the working principle of CNC system,feeding system are analyzed the influence factors of dynamic characteristic and law,the calculation method of surface profile error is studied and the three dimensional animation displaying methods of cutting process,and on this basis,put forward and realized nc machining surface profile error visualization.Specific research contents are as followsThe development of NC interpolation and prospective simulation module is realized.The interpolation and forward-looking algorithms are studied in depth.Considering the constraints of the length and speed of adjacent machining track segments and the connection Angle in forward-looking control,the velocity of the connection point is optimized,and the development of the forward-looking interpolation simulation module is realized.The higher order linear dynamic model of the feed system is obtained accurately.Based on the analysis of the composition of the feed system and the main factors affecting the dynamic characteristics,the excitation signals with uniform speed and pseudo-random sequence were designed,and the dynamic model of the feed system was obtained by the least square method in linear identification,which was used to predict the actual output of each feed shaft in the machining process.A method for calculating surface contour error based on meshing approximation of segmented surfaces was proposed and realized.Firstly,the rough mesh was discretized and the mesh region nearest to the initial point was found.Secondly,the mesh region was subdivided,the nearest point from the initial point was searched and the shortest distance was calculated.Finally,the normal vector direction of the nearest point was determined according to the geometric relationship,and the magnitude and direction of the contour error of the machining surface were predicted.The visualization simulation of CNC machine tool milling based on OpenGL is realized.Based on the analysis of solid modeling method,the STL model of the tool and the workpiece was read,the mathematical model of the tool sweep was established according to the geometric relationship of the tool,and the Boolean subtraction operation was carried out with the data structure of the discrete workpiece to display the tool movement and the machining process,and the visualization simulation of the CNC machine tool was realized...