Research On Thermal Error Modeling Theory And Technology Of CNC Machine Tool

High-grade CNC machine tools is the cornerstone of industrialmodernization, and also is the important indicator of measuring a countrymanufacturing sector level and overall national strength. After years of researchscholars suggest that thermal error of CNC machine tool is the main cause ofmachining error, processing error which caused the whole machine erroraccounted for30%to70%. Therefore, reducing the thermal error of CNCmachine tool is of great significance to improve machining precision. Thermalerror compensation is the most economical and efficient way to compensatethrough modeling software, including thermal error modeling is the coretechnology of thermal error compensation. This paper describes four keytechnologies of CNC machine tools thermal error compensation: theexperimental data collection system; temperature-sensitive point selection;thermal error modeling and thermal error compensation. Paper includes thefollowing:1) Development of high-precision integrated system of thermal errormeasurement; temperature and thermal displacement are integratedreal-time on-line automatic acquisition, on-line data analysis, reportgeneration automatic and so on.2) Scientific method of temperature-sensitive point selection is proposed,through a combination method of fuzzy clustering algorithm and greycorrelation analysis is used to select temperature measurement points. Thecondition that ensuring accuracy is to temperature sensors disposed at leastof.3) Robustness method of thermal error modeling of CNC machine tools isproposed, through the multiple linear regression model, the least absolute,lag model and higher lag model of series models are analyzed andcompared, robustness of each machine axis is analyzed, in order todetermine the optimal algorithm selection.4) Developed a thermal error compensation control system, the use of CNCmachine coordinate origin offset principle to achieve thermal errorcompensation system and the CNC system online communications and thento achieve thermal error compensation, and by thermal matrix chip experiments verify the compensation effect, the final product is Identifiedby Quality Inspection Center of Mechanical Industrial Machines(Kunming).