Research On The Synthesis Error Compensation Modeling Of Cnc Machine Tools

CNC Machine tools will produce processing error in machining process due to various factors within the machine tools, in various error sources of machine tools, the geometric error and thermal error make the biggest part of the total error of the machine tools. Now the CNC machine tools continuously toward the development of high speed and high precision, with the improvement of accuracy of machine tools, geometric error and thermal error will have a greater influence on it. The compensation on the geometric error and the thermal error is very important to improve the accuracy of CNC machine tool. Based on fully understanding and deeply analyzing the current status of research and application of the thermal error and the geometric modeling and compensation technique for the CNC machine tools,some further exploration and research have been done. The primary content of this peper includes:(1) The background and the significance of the research are stated.The status of error compensation technology both in China and abroad are analyzed and the main content of this paper is preaented.(2) The definition of geometric error and thermal error about CNC machine tools and factors which caused them are briefly explained.Also,the advantages and disadvantages of error compensation method and error prevention method are analyzed.Finally,determined that build the thermal compensation model based on multiple linear regression and build the geometric and thermal error model of the CNC machine tools based on the method of polynomial surface fitting,(3) The key technology on thermal deformation of CNC machine tools is studied : the choice of temperature points and the establishment of the thermal error model. First of all, analyzed the structure characteristics and fever heat source of CNC machine tools; Second, obtained the temperature and the error data; Finally, introduced the theory of multiple linear regression,and built the thermal error model based on the theory.(4) The positioning error under different temperatures is detected and the temperature curve and the thermal error curve of machine tools are obtained by processing the datas.(5) Simple interpolation method,curve fitting method and surface fitting method are proposed to predict the positioning error under different temperature. At last,based on the polynomial surface fitting theory build the geometric and thermal error model.